poor fuel mileage and low power

[Chris and Sam]

Hey Guys,



I have a 93 W250 club cab. I've only had the truck a couple months and the fuel mileage around town is terrible around 11 mpg.

Is this normal? The truck is stock. I also think it is down on power. On the highway i get around 20/21 mpg which i thought was great for a truck this size. Any help would be great.



Thanks Sam

 

[Philip]

Do you have gages installed?



If you do have you seen a drop in boost or EGT's?



Do a fuel pressure test to see if your lift pump is working properly.

 

[Chris and Sam]

I don't have guages yet so I don't know what boost psi or egt's.

When I check the lift pump what pressure should it be?



Thanks Again

 

[dpuckett]

Lift pump pressure should be in the 6-8psi at idle, with load dropping to no less than 3psi. I had one that was at 7psi idle, but half throttle in 2nd dropped me to 0.



How old is your fuel filter? Air filter?



Get your gauges in and get back with us. Peak boost for stock intercooled is in the mid to upper teens, with EGT topping out around 1000.



Daniel

 

[Moab4x4]

El Slippo TC?

Does the TQ seem mushy on startup? The big difference between City and Hwy sure makes me suspect a Torque converter or transmission issue.



Not an expert, only an opinionated question.

Ken

 

[jimnance]

Another question along the same lines. I have a 2WD '93 D250 CTD auto. It's getting about 18 MPG on the highway and 16 MPG city. I've been taking it easy, but I recall my old '93 getting more like 20 MPG around town and 22 MPG on the highway.



The engine is smooth and doesn't smoke. EGT's are about 600 F on the highway at 70 MPH, and I haven't seen them go above 800 F on a hill without anything in tow. Boost at full power up the hill is about 18 PSI.



I'm turning 1900 RPM at 68 MPH.



Does all this seem normal?

 

[DKasper]

Yes, all that sounds about normal -- there are a lot of guys that get more mileage out of their rigs, but 18mpg highway is definitely not bad or abnormal. I've had a few different 93's and have yet to score one of the higher mileage machines -- 18-19 is the highest I've had and they have been very healthy trucks.



That said, a lot of guys see mileage improvements when they replace injectors and make other performance mods -- providing they are able to keep their foot out of the fuel!



Dave