Gas mileage!!!!

[19-Silverado-98]

Plugs wires cap rotor. All been done about 2months ago. If that. And I didn't mention I do run mid grade fuel. 265s were on it. I just recently ran a fuel cleaner and internal cleaner stuff through it. Stop to soon possible. Never had a compression test done. Nor have I checked for vacuum leaks. And the plugs are the acdelco platinum plugs. Cant check gap will break the electrode or whatever it's called.

 

[Gatorboy]

O2 sensors

 

[Wstrnsky]

Driving style has the biggest effect on fuel economy.

I honestly wish I could get 11MPG in my truck.

Aww Double digits would be nice!!!

 

[JJZ71]

Aww Double digits would be nice!!!

 

[19-Silverado-98]

Both down stream 02 sensors are new. Bank 1 is about a week. And about 6months on the other.

 

[supertrucker1978]

I remember when 10mpg was great mileage for a truck.

 

[19-Silverado-98]

Well it bothers me cause its a stock truck. Stock. Only thing that has been done to it is things they claim to add mpgs. It seems I'm losing it. I've done a rear diff service about 6 months ago as well. Only thing I've never done is trans service. Scared to. Heard bad news about that. 175k miles and I got it at about 90k and I've never done one. And I'm not sure If the previous owner has. Keep hearing at that long it can break up the build up and mess the trans up.

 

[twomanymontes]

Didn't see you mention if you checked the timing. With that many miles on it the timing chain is sure to be stretched and have some excess slop. That excess slop can retard the cam timing as well as the ignition timing, since the distributor is turned by the cam. I know I check mine bi-yearly with the tune up and it's usually a degree or two off. I get about 11 around town and 14 on the hiway. My truck is stock with the exception of a dynomax 3" exhaust and a K&N drop in air filter.

It only takes a few minutes to check and it might help fuel economy as well as returning some power.

 

[19-Silverado-98]

Yeah I've never checked the timing. Could a worn out fuel pump cause bad gas mileage?

 

[twomanymontes]

Usually not a fuel pump, They kind of either work or don't. Low Fuel pressure [at the injectors] due to a clogged filter could cause a hard start and a massive hessitation, but never had one cause poor fuel economy. I'd think a pump with low pressure would cause the same condition