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Okay I dont care to search through all the threads on this... the short and simple of it is my 92 vr4 gets shitty gas mileage... my "check engine" light comes on periodically so im guessing my 02 sensors are goin out (my engine is a rebuilt with almost 20k on it. so that should be good?)...

WHAT can I do to get better gas mileage? what to replace? do the 02's regulate gas consumption? plugs and wires? i have an hks exhaust, but that shouldn't be killing my gas, same with my intake... and im running stock boost. cruising @ 65 on the freeways in cruise control, no lead foot @ lights, i usually keep it under 3500 Rpms just because my car needs body work so im staying undeer raps I guess... but thats how I drive right now, and i just got 200 miles on a 2/3 tank...

any advice?
 

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yeah i got about 16 mpg on my first tank for my 92tt. (and it seems like you're getting about 15 mpg.) i was wondering if that's normal or not -- it seems low.

to get better gas mileage: shift at 2500 rpms instead of 3000, keep it in 4 or 5 whenever possible, don't race it all the time, and make sure that your car is in good working order.

if your o2 sensor is out, you could have a rich air/fuel mix, which means you're using more fuel than you should be. plugs/wires and distributor cap are the next places i'd check out.
 

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The one thing you might want to check too is how much fuel you put back in at fuelup. For example I thought I was getting like 200 miles on 2/3 of a tank, but the reading on the gas level isnt perfect. I can drive it way below the E level and when the light comes on I still have about 3-4 gallons left in the tank. I figured I was getting 22mpg on the highway with some city driving. Next time you fill up take that much amount of gallons and use that to calculate it with your trip odometer.

The O2's will cause you to use more gas, but this can also be a factor.
 

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Do you have any mods?

I was getting the check engine light along with horrible gas mileage. My o2's were constantly sticking in the rich area even when under light throttle. I pulled the code with the pocketlogger and it was error code #11 - Rear o2 sensor. I thought that my o2 sensors were bad, so I had em both replaced, but had the same problems.

My mechanic had set the VPC / GCC for me and I thought it seemed awefully rich. I turned down the boost to stock levels, then leaned out my VPC / GCC while logging and the o2's started to cycle under light throttle. Looking back I think that the check engine light I was getting was saying that the o2's were out of range... not that they were bad.

Now that my air fuel ratio is in spec I have much better throttle response and gas mileage. When just driving normally I usually shift around 3k rpms.
 
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