Ryan86272

Just Curious on what some problems could make Gas mileage Bad? Im getting less than 200miles per tank.

It is also missing/sputtering in higher RPMS...

Im going to the track Friday and just wanna get this problem fixd...

[ul][*]Spark Plugs[*]Fuel Filter[/ul]What Else could i Try? Injector Cleaner?

MJH78

What is your MPG? how many miles on your car? I'd replace the fuel filter for sure. Now I'm not going to say it's directly related and I don't sell the product myself, but before I switched to Amsoil full syn oil and Amsoil oil filter, I consistently got around 14mpg. 800 miles after the change and I'm getting consistently over 17 (100% city driving).. my driving habits have not changed. things just seem quieter with the motor too...i don't know. I would recommend it though. however the missing is a separate issue..bad plug, COP?

Nolimits31

yea definitley check your COP. that was my problem it stuttered usually at WOT 2000rpm and up

twixxer

my car was doing that, turned out to be the tune.

Derf00

A heavy right foot could cause poor gas mileage

How many miles on the car?

2012White5.0

Fuel filter and injector cleaner are so easy you should just do those anyway. They are also fairly cheap. As for the spark plugs you could always pull them if you have the tools and know what you are doing. That way you can see if they are bad. They say you should change spark plugs every 60,000 miles, some can go longer, it depends on how the car has been driven. If yours is past 60-80k miles on it; it probably wouldn't hurt to have those changed either.

SVTeeshirt

might need some plug wires too.

Derf00

99+ V8 modular engines are Coil on plug, no wires.

enrobriaffej

Im having the same problem as you can see from my post right beside yours. Please PM me and let me know all what you did to fix it(when you get it fixed) I'll do the same if you would like? I'll pick up injector cleaner and spark plugs tonight. Then i'll probably try fuel filter, then fuel pump.

2012White5.0

The 99+ don't have wires, but they have the rubber boots that attach to the COP. If those are deteriorating it can cause an arch which causes it to run poorly. So those may need replacing.