apparently i have a 325ex

[Bolestuff]

I'm getting 14.6 city only. The car has been very well maintained and runs like a champ. I just did plugs, but haven't checked the air filter yet. I get the same millage out of my e46 M3. I do have a problem with an extreme case of heavyrightfootidis though.

[audiquattrot]

I'm getting 14.6 city only. The car has been very well maintained and runs like a champ. I just did plugs, but haven't checked the air filter yet. I get the same millage out of my e46 M3. I do have a problem with an extreme case of heavyrightfootidis though.

+ 1, although i avg 20-21 in my E46 M3 hyway. It gets marginally better mpg than the E30.

The iX runs very strong, new plugs, filter.....i was thinking of changing my O2 sensors, but I don't think it will significantly make that much of a diff. I do have 4.10s in there, so I'm sure that has a lot to do w/ it

[flyboyx]

manual ix's came with the window sticker saying that the epa rated mileage was 17 city and 23 highway. i know this is only a guideline. my ix gets a solid 23 mpg pretty much highway or city. its pretty much bone stock.

op: i would like to think that you did indeed get 30mpg, but unless you drove downhill the entire time, this is pretty unlikely. the chances are that when you filled the car up the second time you didn't get it as full as it was when you started your test. also, 35 miles isn't near enough distance to make an accurate reading because of what i mentioned in the previous sentence.

[e30jake]

I just filled up my "new" ix for the first time after I filled the tank and got 23.7 mpg with between 70 and 80 percent city driving. I have been driving like a 90 year old lady though. Not quite the 30+ I got in my m10 while driving like a jackass, but seems to be better than what most people are getting.

[Kershaw]

31?

you don't have an injector swap do you?

I'm not surprised by 26+ but 31 is pretty hard to swallow.

more like 32, if you round up.

i am running 17.5lb m50 injectors. i figure that is why the obc is off a bit.

i wouldnt believe 32mpg if i wasnt there to see it myself. :o

[JA1991]

Yea i got 31.5 across 1100 miles with no problem. Kept it between 75-80 and when i was going through the mountains or hills i wouldn't give it more gas i'd just let it slow down and then pick back up going back down the mountains/hills.

[flyboyx]

more like 32, if you round up.

i am running 17.5lb m50 injectors. i figure that is why the obc is off a bit.

i wouldnt believe 32mpg if i wasnt there to see it myself. :o

i am sure you know this but you can't judge fuel economy by reading the obc. you have to fill the car, reset the odo. drive out the tank, fill it up again. divide: miles driven / number of gallons. for any kind of accuracy, this needs to be done 3 or 4 times and averaged out.

to get 32 mpg, you would have to get well over 400 miles to a tank of gas.

[nando]

that is exactly why you saw 31mpg. you changed how much fuel flows for a given PW, so now the OBC and econometer don't work because they are based on the stock 14# injector.

you didn't get 31mpg. it would be like putting tires that were 4" smaller diameter, then maxing out the speedometer and saying you went 150mph.

[audiquattrot]

i am sure you know this but you can't judge fuel economy by reading the obc. you have to fill the car, reset the odo. drive out the tank, fill it up again. divide: miles driven / number of gallons. for any kind of accuracy, this needs to be done 3 or 4 times and averaged out.

to get 32 mpg, you would have to get well over 400 miles to a tank of gas.

This is exactly how I calculate mpg too. I Don't have obc in my e30 and wouldn't rely on it....actually I reset my trip every time I do a fill up since I'm OCD about knowing my mpg

[nando]

you can trust the OBC pretty well *if the injectors are stock*. As soon as you change that one constant, which the OBC and econometer rely on for their calculation, that goes out the window..

[downforce22]

I agree with both of you guys ^^ but 30 mpg is not totally unreasonable in an iX, depending on speed, temp and terrain. I just got another 28 mpg tank, of course I was driving like a grandma (65 mph) on the highway, normally 75, and speeding up downhill, but a properly running fresh m20 ix should get 25+ highway. The only way I see to improve to 32+ is to start at altitude and drive downhill a majority of the way. I heard upon 0 throttle the fuel is cut unless at idle. Not 100% on this, but the only way to gain anymore over 30 is to swap to the 3.64 final drive.

[Wh33lhop]

Kershaw, did you seriously just go off of the OBC calculation after swapping injectors?

[325ixa]

obc measures air flow not fuel.

[Kershaw]

1.066 gallons. distance traveled, 33.9 miles.

this was in the original post.

how many of you passed 3rd grade again? ;)

i can not drive a full tank of gas at 65mph, i'd get waay too bored and i'd be late for work. i average 80-85mph on the highway and im no slouch in the city either. i usually get ~23mpg to a tank of gas. if i babied it and kept it strictly highway, i know i could get ~30mpg cross country if i wanted to. but i would never waste my time like that. it's not worth the $20 extra over 500 miles.

i once did this in my rx8, topped off, did a 30 mile cruise @ 65mph and topped off again. 24.5mpg. i cant do that on a regular basis. more like 20mpg.

[nando]

obc measures air flow not fuel.

no it doesn't.

it reads an injector PW signal which it can translate into fuel volume. it knows how far you're going from the VSS input, so it's simply distance traveled/fuel volume = mpg.