Hi guys
Bought a low mileage, no rust 92 D250 a year ago. Mileage is good however with gas prices as high as they are looking for better mileage. It's an auto overdrive so suspect 3.55 rear but unsure how to know. Don't pull anything behind it. Is there a way to get better mileage? If I change rear to 3.07 will I have to do something with fuel delivery system to get more torque? Thanks in advance

 

Do you have any mods on it? Is it 2wd or 4x4? Dont re-gear it, as you never know when youre gonna need to do some heavy towing. You may end up regretting it for sure. Id start with the basics as far as mods to gain some ponies, tq, and maybe a few mpg. First thing would be a mandrel bent free flowing exhaust system, no larger than 4 inch (if it doesnt already have a 4 inch) then a free flowing muffler, next a much less restrictive intake system such as Cold air intake kit with a washable air filter, maybe a less restrictive intake horn/ manifold, keep the same temperature thermostat, advance injector timing a couple degrees, maintain max tire pressure, change to synthetic fluids (gear, engine oil, etc), add injector cleaner additive every 3k miles-ish, dont carry any unnecessary weight. Also, get some guages (EGT, trans temp, boost, fuel pressure), so as to properly monitor what your engine is doing, maybe a bed cover to minimize (or eliminate) excessive turbulence in the truck bed. Keep your driving habits conservative (most importantly) and you will see some improvement. BUT be forwarned....once you start modding your truck, it gets addictive.......
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