The 'fuelly' economy thread

[Click_It]

A quick search didn't reveal recent similar threads so I thought I'd start one. To get us started I have a question regarding my own fuel economy, or lack there of...

I recently set up fuelly (had records dating back 12 months thus the 14 fill ups) and the first thing I noticed is my economy is considerably behind my american counterparts. I'm trying to understand why this is. I live in a hilly area and most of my driving currently is shorter city trips with little highway mileage so this is obviously playing a role. I don't drive hard, I coast in traffic where possible. My B3 is carby, is that also playing a big part? Despite the disadvantages above I still feel I should at the very least be achieving mid 30's. Surely you guys aren't just doing easy highway miles so something is wrong at my end.

Extreme mods aside what might be a few things to look into? I recently changed the fuel filter. Have tried cleaning up the carb, even running injector/carb cleaner through the tank. New spark plugs (although still running old leads), haven't touched the fuel pump yet. Any suggestions welcomed.

And please use this thread to discuss your own fuelly economy too!

[Charlie1717]

Just out of curiosity I see you have 15" rims have you calculated the percentage difference between these and stock? Your Speedo will be off so you may have been calculating your mpg wrong.

Example in my case I have 13's that are 7% larger so I have to multiply my total miles by 1.07 then calculate my MPG

Here is a link

http://www.anycalculator.com/tiresize.htm

Stock tires I believe are 165/70/12?

Also looking at your Fuelly... to get accurate results for MPG you should go atleast 5 gallons worth. I don't remember the reason why but it does make a difference. PU241 knows alot about this subject and getting good mpg/calculating

[link5186]

Good point Charlie! Stock size is 145r12 with 165/70r12 as an option. They are pretty close in size. The 165s throw my speedo off by about 2mph.

[Darlo]

Wow! Only 30.6mpg ave for a 5-spd!

I have tried my hardest to get bad gas mileage a couple times and got it DOWN to 41.4mpg one time! :p

Not sure what you are doing wrong! Give us an update after correcting for the tire size difference.

[Charlie1717]

Wow! Only 30.6mpg ave for a 5-spd!

I have tried my hardest to get bad gas mileage a couple times and got it DOWN to 41.4mpg one time! :p

Not sure what you are doing wrong! Give us an update after correcting for the tire size difference.

I tested his stats with my difference of 1.07 and it would boost him up to around 36 mpg so I'm sure that would be a much more encouraging figure

[Darlo]

36 is still really low! compared to an AVERAGE of 45.7! Something else is wrong.

[91mcnasty]

I run my 91 fuel injected car pretty decent and get at least 40 all the time!

[Charlie1717]

36 is still really low! compared to an AVERAGE of 45.7! Something else is wrong.

Correct but it's much closer to normal than 30. Also that is with my 7% he could be even closer to 40 I don't know. But 40 would be more normal for his car. Especially with the larger 15's I'm sure they are heavier and they take much more to get going, and he stated he does mostly in town short spurts of driving which would bring it down also. Never the less he should still be upwards of 40+

[Tommy]

Im getting about 31 highway with a stock 93gl auto I was getting about 24 almost 25mpg but found that were my intake tube goes into the throttle body was backed off a little causing it to suck more air. I still dont know how to get better mileage out of the car and ive changed the plugs, wires, cap and rotor, fuel filter but nothing not even 1 mpg better.

[fastivaca]

Darlo, don't forget that our 40mpg is about 32 miles per US gallon.

[Pu241]

Darlo, don't forget that our 40mpg is about 32 miles per US gallon.

Think Darlo does his fuelly in US gallons. As we are pretty close in AVG MPG.

[Click_It]

Just out of curiosity I see you have 15" rims have you calculated the percentage difference between these and stock? Your Speedo will be off so you may have been calculating your mpg wrong.

Example in my case I have 13's that are 7% larger so I have to multiply my total miles by 1.07 then calculate my MPG

Here is a link

http://www.anycalculator.com/tiresize.htm

Lots of replies wow. Yeah my tires are 5% larger however I haven't ran a full tank on these yet. I'll be sure to calculate future trips accordingly, thanks for the info. So even with the 5% I'm probably around the 33-34mpg mark. As a few of you have said something is still not right with that. Hmmmm got me thinking now.

[Darlo]

Darlo, don't forget that our 40mpg is about 32 miles per US gallon.

HAHA, I am getting 45.7mpg (US GALLONS) which is 54.9mpg (Imp GALLONS).

I would shoot myself (maybe not with a gun, lol, maybe an elastic band) if I was getting less than 40mpg (US)!

[rollertoaster]

I went up to 41.3 on my first full tank of 89oct e10 after my 5spd swap. I don't drive the car easy, so I'm pleased with the results. If only I could get non ethanol fuel I'd easily get 3-4 mpg more. I hate E10!


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[Click_It]

Okay I was running taller 13" aspire wheel/tires for the last 12 months which were 5.7% taller than standard and added this to those fill ups. Brings my numbers UP to 31.5mpg, still pretty bad though.