Contour Enthusiasts Group Archives Forums General Troubleshooting Bad bad bad gas mileage

I have a 96 Contour GL. 4 cylinder ATX.

I've notice that I have to go to the gas station very frequently so I jotted down the numbers.

After calculations I find that I'm getting 13.98MPG!

This is horrible so my dad is assuming that its the rims or something. He said that since its bigger in diameter than the stock wheels, the mileage is incorrect.

Is that true? Where do the odometer get its distance readings? I use Firestone Firehawk P205/60rs/90H tires if that means anything.

I flushed my cooler tank like 2 months ago but still the same crappy gas mileage.

thanks for your time in reading this post

What size of tires? 14" 15" 16", ect?

But if you are going to the gas station frequenlty, I doubt its just your rims. Someone else will chime in later.

16"
thx

Oxygen sensor(s)? If bad, they will kill gas mileage.

How many miles on the car?

http://www.empireofgames.com/~gladiator/pics/rim56.jpg

I don't know what type of rims they are but this might help

68k miles on the car, it passed all the inspections though.

anyone?

If no check engine light, then?

Fuel leak?
Sticking brakes?
Bad Automatic Transmission?

Just really hardcore driving?

Just a few things to consider.

One more question, when you turn on the key, does the Check Engine Light come on momentarily then go out when the car starts?

TB

Nope, no CEL lights whatsoever. It was on like 4 months ago but I plucked out the battery and it's been off ever since.

Not sure about my transmission and I do not drive hardcore at all. My dad drives it most of the time anyways and hes 70.

So can anyone answer my rim question? Does the size (16") alter the actual readings on the odometer?

Thanks

You need to know the overall tire diameter, not just the rim size. Compare the overall tire diameter of the tires you have now, with the diamater of the stock size tires. If the number is significantly different (more than 1/2inch) then your speedometer/odometer readings will be off.

You can go to Tire Rack's website and look up the size tires you have and it will give you the diameter.

205/60 means 205 mm wide and height of sidewall is 60% of width or 123 mm. 123 mm is 4.84 inches so since the overall diameter involves two sidewalls it is about 9.68 inches plus the rim diameter of 16 so 25.68 inches in dameter over-all.

Stock is 185/70-14 which comes to 24.2 inches overall diameter. So you are only about 6% different from stock. When your odometer says you went 100 mi, you actually have gone about 106.