Why am I getting 11.5 MPG on the interstate?

[94-302-vert]

Have you cleaned your MAF? With my CAI I have to clean the MAF every 6-8 k miles...

 

[legalize420]

i get about 16ish in mine driving about 60/40 highway/backroads on stock 3.08s... driving pretty conservatively. u guys that are running over 20mpg on a consistent basis must all have 2.73s and spend 90% of your time on the interstate, i hardly ever break 200 miles on a full tank.

373 gears here. i get between 260-280 before fill up and usually fit about 13 gallons in there. thats with 50/50 city/highway. if i did only highway driving im sure i could see over 300 on a tank.

 

[1slow95]

My odometer doesnt even work. I checked the distance in my sisters car. Ive been riding to school with her in an effort to save $$. lol

And do gears throw off the odometer even if you have the right speedo gear?

You can't get the correct speedo gear for 3.73's in a 94-95 with the stock t-5. With the 3.55 gear(white) you'll still be off by about 10%.

Driving at 65-70mph I got 18mpg when I took a road trip last summer. I usually get 8-12 around town tho

 

[GreenStangGT]

With the correct speedo gear your odometer should be correct.

Not sure if you have tried any injector cleaner, I have had good luck with the lucas, I ran that in my wife's trailblazer before our trip to florida and loaded down with a/c on and the 5.3L we got 25 miles to the gallon which was a couple mpg better than normal. Also when was the last oil change? That could affect mpg

Not necessarily true. I went from stock 2.73's to 3.73's in the rear and, even with the most correct speedo gear, my speedometer is definitely off. I do second the idea of trying some injector cleaner though. I especially advise using SeaFoam twice, once through the gas tank and once through a vacuum line. I had good results with it and it couldn't hurt.

 

[Black95GTS]

After 3.55s you need to:

1 - Just deal with your stuff being silghtly high with a speedo gear change
2 - Change out the transmission gear and speedo gear to make a different ratio
3 - Use an electronic device such as a Speedcal

There is no single gear to drop in and correct for rear screw changes after you get past 3.55s.

Adam

 

[wytstang]

I would check all the spark plugs and make sure every cylinder is firing clean. A cylinder balance test may lead you to a problem too.
Scott

Jack pot my #8 cylinder was not squirting properly, I pulled the plug and half was black and the other half was normal. The injector was squirting directly at the injector yet is was firing well enough not to miss and or hesitate. Pull the plugs and they will tell you whats happening. I ended buying a whole set of used injectors so if you need 1 or a few I have some.

 

[trav_19]

i have never used a speedo calibration thing i just drive and keep up with traffic i checked it once so i have an idea how fast im going... but i also know my odometer is spinning faster too

 

[The Green GT]

I plan on checking mine with a GPS soon.

 

[gcomfx.com]

If his speedo was off.... mine shows I'm going faster than I am... wouldn't that make your mileage appear BETTER as you are racking up MORE miles on a tank of gas? You could actually be getting 6mpg. LOL Or do I have that backwards?

I would look for a leak. How's the rubber gasket on your tank? Show any signs of a liquid trail?

 

[The Green GT]

I have no leaks. I have never had any liquid drip from my car unless I was changing fluids.

I do have an oil leak though. But it does not drip.

 

[final5-0]

I have no leaks. I have never had any liquid drip from my car unless I was changing fluids.

I do have an oil leak though. But it does not drip.

When I saw this ................

I instantly thought of Saturday Night Live ......... from years ago

They had .............. Church Lady

She would'a said

Aren't You Special

Grady

 

[The Green GT]

Aren't You Special

Grady

Momma tells me that everyday.

 

[gcomfx.com]

You do realize gas won't always leave a puddle right? I've had mine leak on the fuel rail. It never hit the ground. And I had my filler tube gasket leak. It ran down my tail pipe.

 

[The Green GT]

Well I never smell gas, so Im not worried about a leak.