The thing is for a given throttle position you will use less fuel at high elevations since the air density is lower and the ECM will maintain the proper fuel/air ratios or else the car wound not meet emission laws. It's all about using the same amount of work to get up a hill regardless of elevation. A gallon of gas will have the same amount of energy regradless of elevation. If the fuel is burned at the correct ratio to air you will get the same amout of work from that gallon of gas.

Same size hill-same amount of work being done- same amount of fuel used -but the throttle will need to be open more to let the same mass (not volume) of air to be used with that gallon of gas to get up the hill at the lower air density.

BTW I am a senior R&D test technician for an auto supplier here in the "motor city" (Detroit) and work with a few very good engineers. I will talk to them and ask question about this.

 

I understand what your saying. If what you said is true, though, can you explain why cars run the 1/4mi slower at higher elevations vs lower? Back in my drag racing days, a difference of even 1000 feet makes a significant difference in ET. Not trying to argue, just wondering how you/they would explain that.

 

At wide open throttle there is less air pressure to push air into the cylinders thus limits how much fuel can be burned at the best fuel/air ratio. The engine will pump less air mass (not volumm) for each stroke of the pistons at high elevation limiting how much fuel can be burnt.

See, turbos (vs superchargers) are great for high elevation since they just spin faster at high elevation to push more volumm into the engine. It's all about air mass not air volumm. If you take a give mass of air at sea level and seal it in a trash bag and drive it to a top of a mountain what will happen to that trash bag. It will inflate and get very tight. the mass is the same but the volumm has increased. Each stroke of the piston is fixed in volumm ( bore x stroke) so at high elevation the cylinder is using the same volumm but less air mass.

 

I think a lot of times gas stations pump calibrations are off. I have a friend with a Civic Hybrid that checks his gas milage religiously, and he once put in ~2 gallon more than the tank capacity. He called the state inspection line and complained, and later the station was inspected and fined!

 

I'm sure it's the hills of the city. I am currently averaging 33-34mpg, and I drive in SF

 

I just filled up first time, with just short of 300 miles on the car I got 33 MPG. It is a Base model with automatic. I gave the car no slack, always first away from the light and accelerated to speed limit as quickly as possible.

 

Anyone with intake/exhaust either or both have gas mileage for their cars? I figure its the same or better just checking.

 

I'm ay 800 miles and still only averaging about 28mpg.

I drive about 50/50 city/highway.

I'm a big guy (6'3", 280). Could that be the problem?

 

I think it's got something to do with the NJ gas...I'm getting similiar MPG in NY and NJ...it's the wash down blend of gas...

 

This has nothing to do with mileage but I picked this site because there appears to be a lot of people on it. Check out this new spy siting of the next generation of Fit being built in China. Unfortunately, it's all in Chinese. Can anyone here translate and give us a reader's digest version of any differences to the current model? You can definately see that it's a Fit...the style cues are there. If anyone can help out, it'd be great.....thanks.


http://chicago-auto-show.autoblog.co...-chinese-site/

 

New Fit Sport AT: Rural/City driving (35 miles each way to work, takes about 1hr 15 min due to heavy traffic).

1st Tank 312 miles, 9.6 gallons = 32.49 mpg
2nd Tank 309.9 miles, 9.76 gallons = 31.75 mpg
3rd Tank 299.4 miles, 9.95 gallons = 30.09 mpg

At this rate, I'll be getting only 3 mpg after another 11,000 miles or so.

 

Mine has varied anywhere from 32mpg to an amazing 41mpg! in a 6 week span.

 

My area gas stations have been picked apart and I only use the one station that gives the best mileage for all 5 of my cars. That said and no added weight or other major varialbles, I'm still hovering on 33 MPG. This is done on refills of no more than 7.5 gals.
I don't wait for an idiot light. However technically if gas weights ~8.5lbs./Gal your car is lighter by >40lbs at the 1/2 tank rather than the full tank, so your mileage should be better below the 1/2 tank. (Ha.....Ha)

 

Interesting how people aren't even getting 30 MPG. I am getting 35-40 MPG everytime I fill up. I drive 20% City and 80% Highway and have about 1700 miles now.

 

I havent gotten less than 40 ever with a high of 44.68

 

doesnt matter how i drive, i get no more than 26. 12mpg less than advertised. Honda is getting a call from me.

 

I had a 2003 Altima Se with AEM CAI and Stillen Exhaust. I ran it quick and it still averaged 23-26 MPG. This is the 3.5 V6! It had roughly 270 hP. Those of you getting only 28-29 MPG I don't understand. Sure your caluculating your mileage correctly?

 

Pretty damn accurate i think, when the light comes on I filled up till it clicks off and divide the total trip mileage by the gallons pumped in...I do a full reset after each fill up...I just made past the 600 mileage club, so hopefully things would get better...the best MPG so far I got was 26 MPG... and it's not under full load yet with A/C...and I don't step on it either. if things don't improve, i'm gonna make full use of the warranty...doesn't seem right...

 

Mileage report: 312.7 miles, 9.477 gallons. Equals 32.99 MPG. 30 percent highway, 70 percent city.

 

I have Jazz 1.4ES since sept 2002, now 55000km on the clock. Most of it in Switzerland, last 20K in Serbia. In CH, my average for 40km trip (to my office, 14km highway 120kmph, 26km a mix of urbam and extra urban 60-80kmph) it was 5.3l/100km. On strictly highway routes 6,2l/100km
In Serbia it is around 7,5l/100km in the town, goes to 9,0l/100km with AC on and very short trips (2km).
I had a record 5,0l/100km in Serbia for my winter holiday, no highways, plenty of hills (but downhills as well), 15km without warmed up engine (while we were there), and a mixture of 60-80-100kmph roads. I obbey the speed limit+10%. I have two witnesses for this 300km trip. I know I am not very special since a friend in Switzerland made 4,7l/100km in his Jazz 1.4Ls (it is about 60kg lighter) on a mixture of 60-80kmph roads. I do not know what is Fit like, but my Jazz is fourth member of our family, my 3yr old daughter likes it very much, as well as my wife and me. All the best to other Fitters/Jazzers