bad fuel mileage...HELP!!

If you haven't had the overhead run (valve adjustment) that's a good place to start.

 

not all.
boost leaks, old fuel filter, old injector nozzles.... cause poor fuel milage

 

I have the exact same truck.

I was getting 5mpg on average and within 3 months driver was averaging 4.5mpg

I took the truck to Harper Detroit Diesel not Freightliner.
They did a top end adjustments and they told me that my valves were way to tight. The first trip after the work the truck was getting 3.5mpg according to mechanic this is normal on some engines.

The truck has done over 10,000 miles since the work and she is averaging around 6.5mpg this is going through the Virginia mountains and pulling reefer load of 80,000lbs
I have seen 7.4mpg on some trips.

It is worth the investment.

 

If you dont mind me asking- could you tell me how much did that cost?

 

Wow, thats worth it!

 

I am just guessing, but I would think between $280 & $350

 

I don't know what they charge in the USA however in Canada it's $499.

I spent more however that was for additional work.

 

If anyone is in the Atlanta, GA area looking to get the valves adjusted, I can get you info where you can get it done for a good price. PM me if interested.

 

maybe in denver i heard of a guy,also its beed real windy and cold,alott of condensation= water,drain your water seperater,and slow down 5 mph itllbreall make your day,good luck driver