Hypermiling

[SciFion]

This post by Ivan (um_lunchbox) over at the Scikotics forum is very interesting. > http://www.scikotics.com/forums/showthread.php?t=48640 Some of you may have already seen it, but just in case you're interested in achieving incredible gas mileage in your xD, check it out.

Last weekend I was able to get 45 MPG while drafting behind my buddies racecar trailer. I used the cruise control and hovered at 60 MPH for over one hundred miles. My tire air pressue is bumped up 4 PSI over reccomended pressure (still within the safe zone). Even without that draft I can usually get between 37 & 41 MPG using these techniques. If mileage is of no concern, then this stuff wont matter. But the results are impressive and worth checking out if you are trying to save money etc.

I guess hypermiling is nothing new, but it was an eye opener for me, hope it helps.

[Cylon_xD]

This is a big stickler with my xD, it really irks me - I get between 24 and 26 mpg around town and driving back roads to work, and the best I've ever gotten on the highway is 29 - but perhaps somewhat because I pretty much have to drive between 75 and 85 mph on the highways around here - If I tried to drive anywhere close to 60mph I would be road kill for sure...

45 mpg is just totally incredulous to me comparing with my results... Grrr! :emotions122:

[SciFion]

Have you increased your tire pressure a few pounds yet? Try going 65 instead of 70. Coast when you can, it all adds up.

[xDizzle]

tru i try to coast wen i can i notice the difference

[SciFion]

I only got 45 MPG one time drafting behind a trailer at 60 MPH. I can usually get between 36 and 40 MPG when I focus on it. I'm telling you guys, bumping up the air pressure in your tires has a dramatic effect on your mileage. Even if you do nothing else, you will see a difference of a couple of MPG. My stock tires are recomended at 44 PSI, and I put them at 47-48 PSI.

Yeah you feel a few more bumps and can sense more of the road changes, but for me saving money is just that, saving. If your tire pressure is below the maximum pressure indicated on the sidewall, you will not get as good of mileage as is possible. More air pressure equals less rolling resistance, which equals better MPG. In an 11 gallon tank, even 2 MPG improvement is 22 miles, and it only gets better when you focus on it.

When I first got the car, I would get around 320 miles before I needed to fill up. Now when I work on it that number is up to 360 or better. It can be done, but you must change the way you drive. Now I don't always drive like a slug, only when hypermiling!

23

[Scionizer]

I noticed a change with bumping up the tire pressure too...I am averaging 38 to 40 now...and that's with a heavy foot.

[mcbrew]

I don't know what the deal is... but on the last coupld of tanks, I've gotten lower FE than I expected. I have had a hard time keeping above 40 MPG. Well, I can keep the displayed FE near 40-41, but that ends up being more like 37.5-38.5 at the pump. I have been filling up at the same BP station as always... I wonder if it is a different gas formulation... or just the warmer weather the past few weeks. I have been using the A/C a little... but not all the time.

Hey Cylon, my wife and I are driving up to York for the weekend (she still has a house there). If you see a red xD towing a trailer, that's me! Maybe we'll get to meet up at a Scion get-together one of these days... I'd be interested in riding along with you (or you in my car) and see if we drive totally differently (based on my FE vs. yours). Just one of those curiosities.

[Cylon_xD]

Hey Cylon, my wife and I are driving up to York for the weekend (she still has a house there). If you see a red xD towing a trailer, that's me! Maybe we'll get to meet up at a Scion get-together one of these days...

Hey, I'm going to the Scion East Coast Show of Champions at the Capital Raceway in Crofton MD on Sunday, so I'll be down YOUR way that day, haha...

I'll be home Saturday but workin on cleaning up the car for the show at least part of the day... you two ought to come over Saturday night to see a movie in the Frey Theater! :)

http://freytheater.com

[Tim.TRDSparks]

I know that both the generation XB's and now the XD get great mileage while drafting. There aren't many hills here at the beach unless you are on an overpass and thats when I put the car in neutral and coast. I see my mileage jump like crazy on the ScanGauge. This is some useful info for us guys. Thanks!


Tim

[mcbrew]

Cylon, got back from PA last night. I was towing a trailer with a queen mattress, sofa-bed, and a few boxes of books and misc stuff (both on the trailer and in the car). I had about 140 miles with no trailer, 110 miles with an empty trailer, and 110 miles with a full trailer. I filled up when I got home and got 35.9 MPG (38.something on the display). My real-time MPG was showing as low as 15 MPG going up some of those hills on 83!

[Cylon_xD]

Ha, we might have even passed each other on 83 Sunday night - I was driving north on 83 between about 7:00 and 7:30 pm... I wasn't thinking to look for your car, though... :)

I won 1st place in the xD division - a repeat of last year's win - and SnuGG won 2nd place...!

[mcbrew]

Congrats! I was already at my friend's bonfire by 7pm. I wasn't far from Crofton, though.

[mcbrew]

I just towed the trailer back up to York to pick up more stuff from the wife's house. I filled up just after leaving home. With 100% trailer towing, I'm showing 46 MPG in the display. Of course, the trailer is going to be loaded up on the way home... but I'm going to try to keep the mileage up as best I can.

[Cylon_xD]

Hey well, I've been getting a good solid 12 mpg on the highway with my Dodge Ram 4x4 pickup driving to work these past two weeks, lol!! :mad:

I had to stop driving my xD to and from work for the time being, because they're repaving the highway and left 2" or 3" lips where the asphalt stops and starts at the bridges and underpasses where they're working now - hitting them at 65 mph in my lowered xD with 40 series tires, I'm bottoming out slammin' the struts so hard it makes the car hop 6 inches into the air. I'm afraid of breaking another wheel or ripping out the strut towers in the front... :mad3:

Doesn't look like they'll be finishing the paving anytime soon, since their concentrating all their work on the bridges right now, could be months till they finish the asphalt at the bridges and underpasses... so i'll be taking a painful hit at the gas pumps for a while... :boxed:

[mcbrew]

Wow, if the bumps are that bad in the xD, imagine what happens to a horse and buggy! Just got back from York with a huge load: full size mattress, box spring, frame, headboard, two tables, a work bench, etc. Got about 32-33 MPG (35 showing).

[Cylon_xD]

You must be running on only 3 cyliders or something, Brew, lol! My drive to work is about half highway driving and half 50 mph country roads, and I'm still only getting about 27-28 mpg... I have yet to break the magic 30 mpg barrier in my xD, even on a longer all-highway trip...

oh, and the bumps are that hard on my xD because the drop is very low in the front with the progress springs - about a half inch lower than Tanabe DF's even... so I have less than two inches of piston movement on my struts before they bottom out... doesn't take much to slam them!

[mcbrew]

You must be running on only 3 cyliders or something, Brew, lol!
What, you use all four? lol! Because I was worried about losing something out of the trailer at high speeds, I kept the cruise set at 50 MPH most of the way home.

oh, and the bumps are that hard on my xD because the drop is very low in the front with the progress springs
I can believe it... I've got the TRD suspension parts, and bumpy roads are quite noticeable. I've gotta be more careful with my morning coffee than I did when I drive a Golf.

[mcbrew]

Just got another 40+ tank... 41.3 MPG to be exact. The display was showing about 44 MPG. For most of the tank, I had it up to 47-48 MPG (on the display), but I killed that with some higher-speed driving and then driving in town to avoid backup on the DC beltway.

[MoFaux]

I'm not getting 40+, but I am averaging around 34 MPG. On the highway I can get 40-41, but with a family we do a lot of around town driving and that kills the mileage.

I can't believe some are getting sub 30's. From what I can tell you really gotta be hammering the xD to push the mileage that low. :boxed:

[Cylon_xD]

Nope, just normal driving with manual transmission. I've gotten as low as 24 mpg on one tank, when I WAS beating the car quite a bit, but that was shortly after I got it, maybe the third or fourth tankfull, and that was before I added any mods like wide wheels and tires or intake filter or axleback exhaust or anything else to the car... I suppose the mpg's on my car are basically close to the rated values, but just a couple mpg below them... instead of 27/33, I get more like 26/29... Ah well.

[mcbrew]

Cylon, I still think there's something odd about your xD...

The lowest I've ever gotten was 30.7 MPG (calculated... was about 32 on the display)... and that was towing a pretty heavy trailer.

My lifetime average is:

http://www.fuelly.com/sig-us/15039.png (http://www.fuelly.com/driver/mcbrew/xd)

[chingPO]

the lowest I've gotten was 26-27 and that was when I was always rushing to work with fast accelerations(stepping it all the way ALWAYS) and very hard stops w/ the recommended tire psi. And I try not to carry any additional weight except for myself and I weigh about 165lbs at that time.

Now that I lost weight and increased tire pressure by 4psi, started putting on neutral gear whenever I see a red light and started to accelerate slowly when on a dead stop(w/c is damn hard coz I really like the VROOOM sound) I am averaging 33-34 with combined city and highway driving. I really like to fast and its verry verry tempting to do so. I can't really keep my speed on the highway speed limit of 55mph unless I'm texting while driving.

[TheLittleDeviant]

I can't really keep my speed on the highway speed limit of 55mph unless I'm texting while driving.


LOL, sounds like a news report waiting to happen...

[Cylon_xD]

Just filled up yesterday and checked the mileage, 280 miles on 10.02 gallons so that's exactly 28 mpg. This tankful was strictly driving back and forth to work, about 1/3 highway, 2/3 country roads at 35-50 mph, and one 100 mile round-trip to a remote office that was 80% highway driving at 70 mph average...

And remember, I weight about 310 pounds... :disgust:

[mcbrew]

Towed my trailer up to York again this weekend. Me (220#), my pregnant wife (won't put her weight in case she reads this post), a trailer full of stuff (about 1,000#), and the back of the car full (another 200# or so). I got 32.5 MPG actual (35.0 MPG on the display).

[mcbrew]

They must be phasing in the ethanol again... my last few tanks have been right around 37-38 MPG, and that's going pretty easy on the pedal. I might not see another 40 MPG tank until next summer.

[TheLittleDeviant]

They must be phasing in the ethanol again... my last few tanks have been right around 37-38 MPG, and that's going pretty easy on the pedal. I might not see another 40 MPG tank until next summer.

Mine has dropped to around the same as yours, you are probably right... I couldnt understand why the drop in mpg...

[CURL'S TIRE AND AUTO]

They must be phasing in the ethanol again... my last few tanks have been right around 37-38 MPG, and that's going pretty easy on the pedal. I might not see another 40 MPG tank until next summer.

Guys, they don't "phase in" ethanol. it's a federal mandate as of last year, that ALL fuel and grades must contain at least 10% ethanol. It IS NOT ILLEGAL for any gas station to advertise "ethanol free" gasoline, it's just not true per the federal mandate. I lived in the Alexandria, Va. area from JAN. 07-APR.08 and i found the levels in that area range from 15% to 20% due to the smog requirements per the EPA. I just let my parents borrow the xD for their anniversary over the weekend. My folks averaged 36.6mpg over the trip of 1457.8 miles running 80+ on the highways. My old man loves it so much, he is trying to buy it from me. NOT GOING TO HAPPEN,lol!

[mcbrew]

Guys, they don't "phase in" ethanol. it's a federal mandate as of last year, that ALL fuel and grades must contain at least 10% ethanol.

According to the information I have, only ten states have E10 mandates (Florida being the only one on the east coast). Ethanol blends are used elsewhere, and E10 makes up approximately 2/3 of the US gasoline supply. My info could be outdated, but I couldn't find anything more recent.

The Energy Independence and Security Act of 2007 requires that 4.7 billion gallons of ethanol be used in our gasoline supply. That number goes up to 36 billion in 2022 (21 billion of which cannot be derived from corn).

[hep2]

I drive my 08 xd 110 a day on 50+ country roads,a few freeway miles at 70,and the rest at 60 with stock tire pressure,standard transmission and consistantly get 42 mpg,thats 400+ per tank except in the winter when they put that crappy gas in the pumps then it dosent matter what you drive or how you drive your milage will drop by allmost 15% if you change nothing else,I dont get it,this winter gas is suppose to help reduce smog but how can that be if you have to burn 15% more to go the same distance?I have noticed this with any car I drive.

[Cylon_xD]

yeah, must be nice, I still have never gotten more than 320 miles per tank, on fumes, even with highway driving.

[CXTKRS1]

lulz my average is 26.6 and my best is 27.8.

[mcbrew]

:adminpower:yeah, must be nice, I still have never gotten more than 320 miles per tank, on fumes, even with highway driving.

Maybe its the wheels...

By the way, I've been watching all the episodes of the original BSG TV series at work on my iPad. Gotta love it.

---------- Post added at 09:54 PM ---------- Previous post was at 09:45 PM ----------

lulz my average is 26.6 and my best is 27.8.

All city? Lots of stop and go driving?

I just filled up a few hours ago and got 38.1 MPG calculated (40.3 displayed). Of my latest nine fill ups, only one was below 37 MPG. That was a very rainy week... Which seems to lower my MPGs no matter what I do.

My commute is mostly highway, but I have been driving a little faster than normal. I have seen speeds of 80+ MPH on certain stretches of the commute. Most of it is 55-60 MPH, though.

I'm going to try to take it easy on this tank and see if I can break 40 MPG for real.

[Cylon_xD]

Maybe its the wheels...

By the way, I've been watching all the episodes of the original BSG TV series at work on my iPad. Gotta love it.

I actually get a little better mileage now with these Katana wheels than when I had the stock wheels on...

Cool, I liked the original Battlestar Galactica series too, I was in high school when it aired on TV in the late 1970's, so I watched it pretty faithfully... but it still can't hold a candle to the new series! :)

Unfortunately, I have yet to break open my Bluray box set of the new BSG series I bought over 4 months ago; I've seen it in it's entirety on TV, and twice on DVD already... I'm waiting to find someone to watch it with me in The Frey Theater - check this thread out, McBrew:

http://www.hometheaterforum.com/forum/thread/292691/the-frey-theater-diy-but-better-every-month

Now THAT's the way to watch a bluray Scifi TV Series! :hands:



Lol, sorry for the thread-jack!

[mcbrew]

Nice theater! I live in a house that's too small and oddly shaped for a projector system... But my father has a nice setup with a 120" fixed screen and a Sanyo LCD projector. I think most ofnhis speakers are Polk in-wall units. I can't remember what the sub is. He's got a Carver amp, too... A 1,200 watt model that drives his 901s (music only).

[JDMJim]

weight ballast( including ourselves), rolling diameter of the rims, inertial weight of the rims, climate control setting, driving with the windows down on the highway etc etc. all are factors. setting the vents to the defrost setting even with the switch off still engages the A/C as well as the temp setting too far in eithe rdirection will trigger the compressor too. try playing with those settings.

here are some of my distances. Chicago to Toledo or Indy leaves me with, say, 3 bars on the gas gauge. that's with a 70-75 mph speed with mostly cruise, three people and luggage

[mcbrew]

I only got 32.1 mpg on my last tank... But I was towing my trailer for most of that tank... And 90+ degree weather doesn't help.

[CXTKRS1]

:adminpower:

Maybe its the wheels...

By the way, I've been watching all the episodes of the original BSG TV series at work on my iPad. Gotta love it.

---------- Post added at 09:54 PM ---------- Previous post was at 09:45 PM ----------



All city? Lots of stop and go driving?

I just filled up a few hours ago and got 38.1 MPG calculated (40.3 displayed). Of my latest nine fill ups, only one was below 37 MPG. That was a very rainy week... Which seems to lower my MPGs no matter what I do.

My commute is mostly highway, but I have been driving a little faster than normal. I have seen speeds of 80+ MPH on certain stretches of the commute. Most of it is 55-60 MPH, though.

I'm going to try to take it easy on this tank and see if I can break 40 MPG for real.

Yep I would say around 90% city driving.

[Cylon_xD]

Eh, all you hyper-milers can just bite me... LOL!! :bleh: jk!

[CXTKRS1]

Eh, all you hyper-milers can just bite me... LOL!! :bleh: jk!

X2 :bleh:

I don't really do anything to help save on mpg's. I drive like a bat out of hell and never park to go inside for fast food.

[YELOSUB]

Even with my 18" rims and heavy a$$ system (plus I weigh 205) I still consistently average anywhere from 34-36 mpg with mixed city/hwy...I have an automatic BTW...I can easily squeeze 360-370+ miles out of a tank if I drive with a light foot...

[CXTKRS1]

24.38 mpg with this last fill up.

[mcbrew]

I'm sitting right at 46 MPG for this tank. I'm just over 200 miles into the tank at this point. I'm hoping to get through the tank without having to tow my trailer. If I can, this will probably be my best tank yet. I'm guessing 46 on the display will be a little over 42 Or 43 MPG in real life. I'll post results in a couple of days.

I have to deliver a keg fridge to a customer some time in the next week. It's going to wreck my mileage since I have to tow the trailer about 70 miles.

[TexXBox]

I manage about 25.5 in mixed driving. My old first gen box did better and I drove it harder.

Even on the highway I have never done better than 30 ish. Although my mpg readout begs to differ. I would think that with an entirely stock drive train, wheels and tires that the computer would not be 4 or more mpg off the calculated mpg via the odometer and gallons.

[mcbrew]

Tex, you do a lot of city driving, or a lot of traffic? I'd have to look back at my records, but my lowest was still 30.something, and that was towing a 1,600 pound trailer! I do keep the top speed down these days... I don't drive like I did 15 years ago. To get over 40, I have to keep it to 55 MPH or lower, upshift early, accelerate slowly, and avoid driving in town.

My display was at 46.0 when I left the house this morning, and it is at 45.1 now. Most of that is due to the rain. I don't know why, but I always get lower FE when it is raining.

BTW, my display has always been 1.5 to 3.5 MPG high... 2 MPG high most of the time. No rhyme or reason to it, either... Not like it is off by a certain percentage. This is the first car I have owned with a built-in MPG display... But I know a lot of people who have them, and almost every one of them reads a few MPGs high.

Oh, and I'm a big Douglas Adams fan, too!

[TexXBox]

Yeah, lots of city, lots of traffic. I live in the DFW metroplex. I can be driving anywhere from 5 to 60 mph on the same street, city or highway, within just a few blocks. My xD seems to run about 500 to 6oo rpm lower than my xB did at the same road speed. I drive the same routes at the same times as I did before and used to routinely get 28.5-29.5 in the B. Manual trans in both cars.

Such is life.

BTW: Is the throttle response of your car a little "soft"? Like there is a subtle lag between the pedal and the engine? I have driven several cars with electronic throttle bodies and don't remember noticing it before. They were either automatics or high horsepower rides though, so that might have masked it. I have not driven any other xD's to have as a reference to use for my car.


Keep your towel close by at all times. :)

[mcbrew]

I ended up with 42.2 MPG on this last tank... The display said 44.8.

Imam probably not right person to ask about throttle response. This is the first car I have owned with a throttle, electronic or mechanical. All of my other cars up to this point have been diesels, and they have had either mechanical or electronic "throttle", but of course diesels don't really have a throttle.

[TexXBox]

I can't imagine ever managing 40+ mpg in my car.

And diesels do have throttles. They just regulate the fuel flow instead of the air flow. Even a stationary engine that operates at a fixed speed has a throttle, that is how it is set to the desired rpm.

[mcbrew]

I mean "throttle" as in the dictionary definition -- to restrict airflow; choke. Most diesels do not have anything that restricts airflow. No throttle body. Air passes freely into the combustion chamber (most often under pressure, since most modern diesels are turbocharged), and (as you said) fuel is adjusted to meet demand. Diesels do not have a tight stoichiometric ratio like gasoline engines.

It is common to refer to the pedal and fueling system of a diesel as the "throttle". Similarly, many people refer to the variable geometry system of a VNT-style turbocharger as the "waste gate". In fact, those turbos don't have waste gates.

Over on the diesel forums, you would get heckled for saying a diesel has a throttle... Just like mentioning your "gas mileage" or your "gas pedal".

---------- Post added at 12:33 AM ---------- Previous post was at 12:31 AM ----------

Oh, and I won't be getting stellar mileage on this new tank. I just hitched up my trailer. I have to tow it to work so that I can deliver a keg fridge to a customer tomorrow.

[TexXBox]

Actually I do mean the dictionary definition as well.

A throttle is the mechanism by which the flow of a fluid is managed by constriction or obstruction. An engine's power can be increased or decreased by the restriction of inlet gases (i.e., by the use of a throttle), but usually decreased. The term throttle has come to refer, informally and incorrectly, to any mechanism by which the power or speed of an engine is regulated.

Since both air and fuel are fluids and you regulate the fluid (diesel fuel) intake of a diesel compression ignition engine to regulate its speed, you are indeed "throttling" it.

Just pickin' nits. :)

[mcbrew]

The term throttle has come to refer, informally and incorrectly, to any mechanism by which the power or speed of an engine is regulated.[/SIZE][/FONT]
I certainly agree with that part.

Just pickin' nits. :)
Yeah, I agree with that, too! :signs8:

---------- Post added at 08:35 PM ---------- Previous post was at 08:33 PM ----------

By the way, I towed my trailer about 75 miles, so my displayed MPG is down to 40.3 MPG right now. I have to tow some stuff to the dump tomorrow, that's only 10 miles round trip. I'm trying to keep it over 40 if possible.

[wooly willy]

I just got 39.7 (on the display) on the way back to school across ohio. 60-65mph average.

It's weird that we can get between 22 to 42 mpg depending on how you drive... most of my family's cars would have a tighter range, the buick got 27-32. the van got 20 no matter how hard or gently you drove. But a ~20mpg difference between gunning and babying is a little absurd to me.

[mcbrew]

willy, it is my experience that the more efficient a car is, the wider the possible range will be.

You should see the numbers over at TDI Club -- there are people getting 25 MPG and 60 MPG with the same year and model TDI.

I used to drive a 1983 Mercedes 300D (turbodiesel). It got 26 MPG no matter how it was driven. If the fuel economy was 25 or lower, I knew it was time to replace the air filter.

[TexXBox]

I guess I need to buy some lighter shoes or I'm destined for sub 30mpg. :)

Jesse, those 300d's were the Timex of cars, "Took a licking and kept on ticking". They were just about impossible to kill unless you hit them with a semi. And even then they would probably drive off anyway.

If you remembered to change the oil regularly, changed the fuel and air filters every so often and threw a can of Lubri-Moly in the tank occasionally they would easily hit 500k.

[JDMJim]

I've been pussy footin the car lately. 30mpg city

[mcbrew]

I guess I need to buy some lighter shoes or I'm destined for sub 30mpg. :)

Jesse, those 300d's were the Timex of cars, "Took a licking and kept on ticking". They were just about impossible to kill unless you hit them with a semi. And even then they would probably drive off anyway.

If you remembered to change the oil regularly, changed the fuel and air filters every so often and threw a can of Lubri-Moly in the tank occasionally they would easily hit 500k.
You're not kidding. My '83 had 410,000 miles on it when I sold it... and it is still a daily driver. I see the car around... and it has over 600,000 miles on it now. My brother bought a 1981 240D when he was 17 and sold it when he was 28. Not only did it have over 600,000 miles on it... it was still on the original clutch! I don't know if that one is still on the road, but it was still going strong when he sold it.

[JDMJim]

i got up to 33.9(display) and we had a really humid day. had to use AC and dropped that sucker to 33.0(display). Now it's 40-60 degrees here. stuck at 33.3

[TexXBox]

So that's what it is..... I have to run my A/C in the damn 105+ degree, 90+% humidity Texas summer. When Fall falls I'm destined to get epic MPG.... :)



Not.

[JDMJim]

what that means is i used the AC on said humid day....

[justjohn]

city driving i got 30 to 31 mpg...

[wooly willy]

I guess I need to buy some lighter shoes or I'm destined for sub 30mpg. :)

I never drive with shoes on, (I know you are just joking...) but I feel a little more connected to my car. It feels less clumsy to me.

Plus, I'm one of those shoe-hating hippie types...

[CXTKRS1]

I never drive with shoes on, (I know you are just joking...) but I feel a little more connected to my car. It feels less clumsy to me.

Plus, I'm one of those shoe-hating hippie types...

It does take a little adjustment if I go from steel toe wear Dr. Martins in jeans to regular shoes in gym shorts.

[mcbrew]

I got 26.8 MPG (calculated -- the display was about 27.something) towing this thing around:

http://i17.photobucket.com/albums/b91/jmcbrew/Scamp/a31f56bb.png

Most of it was local driving... I hope to get one or two MPG better once I get it out on the highway.

[JDMJim]

250 miles total with 3 bars left. dash says 33.8mpg. topped 34.4, but that's it for city for me without being a total putz around town

[FBI]

2 bars left and the dash says 36.4 mpg. City and highway for me. This is still my complimentary tank of gas from the dealership. If this is what I will average on my weekly commute and weekend driving I will be very happy with my choice. I have only had the car 6 days.

[JDMJim]

fresh tank of gas, new wheels on, 34.1 avg so far. now it's rainy and cold again. means the A/C-Deforster has to be on. killin my hypermiling fun here

[FBI]

Second tank of gas. The dash says 35.7. Fill up calculation = 33.8.

I wouldn't call it hypermiling but I am happy because that mileage is a combination of about 60% highway and 40% city.

btw 333.9 miles with the gauge blinking at me.

[JDMJim]

wow. I am doing 32 all city

[wooly willy]

I'm at 28.5 city, are you just babying it or am I being too aggressive?

[JDMJim]

babying like a mofo! I hate it too. But i really am in no hurry. all the roads are 40mph anyway

[wooly willy]

Hahaha, nicely done, Jim.



Do any of you use any other grade of gas, like Premium? Any noticeable difference in gas mileage or power?

[mcbrew]

Premium usually results in slightly lower power and fuel economy. Fewer BTUs per gallon than regular.

[wooly willy]

Interesting. I've always heard the exact opposite but never any explanation or proof, but in doing some googling (inspired by your post) you seem to be correct.

I guess I'll stick with the cheap-o gas!

[JDMJim]

if you plan on being in VVTLi all the time, use high octane. I have been using 89 recently

[mcbrew]

Unless you've done an engine swap, an xD doesn't have a VVTLi engine. We have VVTi -- no valve lift adjutment. Yes, there is a VVTLi version of this engine available... for instance, in the Lotus Elise.

Our engines have nowhere near the compression that requires or gains any benefit from premium gas. Regular gas ignites easier, and is what most engines are designed for. Engines with higher compression use premium and usually produce more horsepower... but it is due to the engine, not the gas. Premium gas is used ONLY to eliminate preignition (knocking) in high compression engines.

[JDMJim]

sorry, i got trigger happy. but it's dual VVT-i. regardless, if you are gonna drive in Vtec all the time, use high octane

[FBI]

Unless you've done an engine swap, an xD doesn't have a VVTLi engine. We have VVTi -- no valve lift adjutment. Yes, there is a VVTLi version of this engine available... for instance, in the Lotus Elise.

Our engines have nowhere near the compression that requires or gains any benefit from premium gas. Regular gas ignites easier, and is what most engines are designed for. Engines with higher compression use premium and usually produce more horsepower... but it is due to the engine, not the gas. Premium gas is used ONLY to eliminate preignition (knocking) in high compression engines.

Interesting; I read a piece on Spitfire Fighters in WWII. A great fighter but needed more climb to go head to head with the Me109. The US started supplying fuel at 100 octane rather than 89 which improved the HP of the Spitfire and gave the pilots a little edge in the Battle for Britain. I have put racing fuel in my Hyundai before and noticed a significant increase in power.

[JDMJim]

might be the altitude tho when it comes to planes. the Thunderbolt even used Alcohol injection for that get away speed

[mcbrew]

If your engine is knocking, you'll get a CEL. Unless that is happening, there should be no benefit to premium gas in our engines. "Butt dynos" are not very well calibrated. Your car might "feel" different with premium gas, but I doubt there is more power. There is no reason there should be more power. There is a good reason there should be less power: there are fewer BTUs per gallon in premium than in regular. By a very small amount, though... probably less than most people could detect.

Running premium will not hurt your engine... it just won't have any benefits, all else being equal. There is a catch there... because all else might not be equal. There may be other additives in the premium, or it may be a different brand than you usually use. I suspect that it is mostly a placebo effect. If anyone has dyne numbers that show otherwise, I will listen.

The same thing happens with biodiesel vs. regular diesel. Biodiesel has a lower BTU content. A given engine will have lower fuel economy and lower power on biodiesel, but many people report having more power. The reason is mainly that biodiesel makes the engine run quieter, so it seems like it isn't working as hard. The difference is small... but lower BTU content equals lower power. This is the same reason that E85 returns much lower fuel economy than regular gasoline or E10. Ethanol has a much lower BTU content than gasoline.

[JDMJim]

you watch Sid the science kid?

[mcbrew]

you watch Sid the science kid?
No, but I do have a 400 gallon biodiesel processor.

http://i17.photobucket.com/albums/b91/jmcbrew/Biodiesel%20Stuff/Pumpsandpipes02.jpg

http://i17.photobucket.com/albums/b91/jmcbrew/Biodiesel%20Stuff/Lookingin.jpg

http://i17.photobucket.com/albums/b91/jmcbrew/Biodiesel%20Stuff/Sampleoffirstlargebatch.jpg

[wooly willy]

shiiiit. What do you run on all that biodiesel?

(Should've bought the 1.4L diesel Urban Cruiser, methinks?)

[TexXBox]

It's a still in disguise..... Don't tell the Revenuers... :)

[JDMJim]

ooo ooo ooo! lately I have been driving to keep up with traffic flow. read driving like all the other asshats. down to 31mpg guage. imagine what the GMC Acadia's are doing....15?

[mcbrew]

:adminpower:shiiiit. What do you run on all that biodiesel?

(Should've bought the 1.4L diesel Urban Cruiser, methinks?)
I used to drive a VW Golf TDI. So did my brother. My parents both drive Jetta TDIs. My cousin drives a Jetta TDI and a Mercedes 300SD. We also have two diesel tractors, two diesel vans (a Chevy and a Mercedes), and a motorhome. Oh, and one of my best friends drives a Jetta TDI, too. I used to drive the sprinter van 750 miles in one day, three times every month... not to mention local driving. My brother and I both put about 80 miles a day on our cars. My mom drives about that much, too.

We don't use nearly as much diesel these days. I'm thinking about selling the biodiesel setup. Anyone interested?

I won't be winning any hypermiling contests this weekend... I'll be towing the camper over to Maryland's eastern shore for some good ol' camping! Me, wife, baby, dog, and all our stuff... not to mention the camper itself. I'm going to take it easy and see if I can get 25 MPG (in the display, at least).

[TexXBox]

I won't be winning any hypermiling contests this weekend... I'll be towing the camper over to Maryland's eastern shore for some good ol' camping! Me, wife, baby, dog, and all our stuff... not to mention the camper itself. I'm going to take it easy and see if I can get 25 MPG (in the display, at least).

You can do it. Probably even with the emergency brake on. :)
Have fun and stay safe.

[FBI]

31.35 Miles/Gal. by tank calculation.

90% of this tank was city driving.

I filled up next to the interstate today then drove 60 miles and the dash read 38.4 miles to the gal/avg. when I got off the interstate.

Love this car!

[wooly willy]

Just did 8 hours on the highway with the dash reading 39.9 almost the whole way. Hell yeah, cruise control set between 60-65mph.

[mcbrew]

I got 25.7 MPG towing the camper this weekend. All but about 20 miles on that tank were with the trailer in tow. I know I would have gotten 0.5 to 1 MPG better if I didn't have to drive through town to do some shopping on the way home. Not bad though...

[FBI]

Just did 8 hours on the highway with the dash reading 39.9 almost the whole way. Hell yeah, cruise control set between 60-65mph.

Awesome!!!

[mcbrew]

Awesome!!!

What ev... I'm showing 43 MPG in the display, and that's my commute to work, not some lazy highway drivin'!

Nah, I'm only kidding. Anything better than the EPA's highway ratings is pretty good... and 39 MPG is 17% better than that. Rock on!

My all-time average is still only 36 MPG... but that includes a LOT of trailer towing... so that's my excuse.

[FBI]

35.6 MPG tank calculation. The dash says 38 MPG even. I love the mileage, love the car, but I am beginning to wonder if the rest of the gauges are that far off.

[MoFaux]

Something I have noticed on the MPG gauge is that if you are sitting at idle not moving (ie. at a stop light or parked) the MPG gauge does not add to the calculated value. So, if you do a lot of stop and go driving the gas you are burning while at the lights is not figuring into the overall mileage reported by the in car gauge. This probably will not account for all the difference we see in the gauge compared to actual mileage but it would account for some.

My question is, if the gauge is not registering mileage at 0 MPH, at what speed does it actually start to track the MPG?

The reason I noticed this was that I was sitting parked with the engine running for almost an hour (it was cold outside and I wanted heat and music). I was sitting there thinking, "this is gonna kill my average MPG". But, when I checked it had NO impact at all on the MPG reported by the gauge.

[mcbrew]

Interesting... mine DOES steadily go down as my car sits at idle. I'm not sure why yours wouldn't do it, too.

---------- Post added at 10:19 PM ---------- Previous post was at 10:17 PM ----------

By the way, I got 25.2 MPG (calculated) on my last tank. 100% of that tank was towing my camper. I thought it would be even lower, because the campground we stayed at was in the hills... and a few times I was cruising uphill at 30 MPH in 2nd gear (35 MPH roads).

[FBI]

36.1 mpg by tank calculation. The dash says 38.0 mpg this time.

[JDMJim]

my meter calculates idle time. took a 80 mile trip this weekend, going north was 38mpg in the heavy rain. going south droppped to 33. wind is everything. been fairly windy since and been stuck at 33 now. My wife drove up north today ( nearly 65 miles or more) and topped 60mpg in her Prius. again, that 35mph south wind blew her along. can;t wait to here the drop coming back against that wind. I hope the direction swings around before she leaves

[FBI]

34.27 mpg with tank calculation. The dash reads 37.3.

[FBI]

33.6 mpg by tank calculation this time. The dash reads 36.8mpg. A lot of town and city driving this tank. Coming up on my first oil change.

I have run six tanks of gas through my xD so far and I am getting 34.14 mpg averaged over all six tanks. 1 mile a gallon over sticker.

Love this car!!!

[wooly willy]

I've been doing mostly stop and go BS around campus, so my average has been 22 on the display. no fun.

[JDMJim]

well, cold is here. 30 or less till spring

[TheLittleDeviant]

Raising the dead a bit here, but the wife has been driving the deviant. Averaging 50+ MPG!! whaaaaaaaaaaaaaaaaaaaaaaaaaaaa!?!?!?!?
I felt like a fool when I checked the math and found her to be right, she was at 50.7... My highest ever was 43.5...