small exhaust causing poor mileage?
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small exhaust causing poor mileage?
Hi, I just junked an '82 gmc that weighed 7000 lbs, had 4.10 gears and no overdrive that gave me 11 years of trouble free service from the old 6.2 n/a.
I bought a '91 f250 4x4 x-cab that has been turboed (hypermax),to pull a fifth wheel cuz the jimmy struggled to pull it. from the day I bought the gmc it got 17 mpg while i only get 10 or 11 out of the ford that is almost a ton less in weight, has a five speed and 3.54 gears. whoever put the turbo on left what i am guessing is the stock exhaust (two to 2 1/4 in could this be the cause of the mileage being that bad?
thank you.
I bought a '91 f250 4x4 x-cab that has been turboed (hypermax),to pull a fifth wheel cuz the jimmy struggled to pull it. from the day I bought the gmc it got 17 mpg while i only get 10 or 11 out of the ford that is almost a ton less in weight, has a five speed and 3.54 gears. whoever put the turbo on left what i am guessing is the stock exhaust (two to 2 1/4 in could this be the cause of the mileage being that bad?
thank you.
Post Fiend
Joined: Nov 2003
Posts: 21,285
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From: Nutter Fort, WV
bigugly'82,
Welcome to FTE and the IDI diesel forum.
The small exhaust is causing a lot of extra backpressure, which is causing the turbo to not spool well.
I imagine the boost is rather low because of the backpressure, which means you probably have your foot in the throttle most of the time.
That is where the fuel is going.
Your 91 extended cab 4x4 should be over 7,000 pounds empty, I would guess close to 7,500 pounds.
Welcome to FTE and the IDI diesel forum.
The small exhaust is causing a lot of extra backpressure, which is causing the turbo to not spool well.
I imagine the boost is rather low because of the backpressure, which means you probably have your foot in the throttle most of the time.
That is where the fuel is going.
Your 91 extended cab 4x4 should be over 7,000 pounds empty, I would guess close to 7,500 pounds.
