I'm seeking advice on accessories or kits to improve mileage on my Suburban.
I am considering a K&N filter kit (FIPK - Fuel injection Performance Kit)
for the intake side, and am looking for suggestions for exhaust. Borla does
not make a system for this truck, any suggestions would be welcome. I'm
looking for mileage increases, however small, and hoping not to make it
sound like a teenager's hot rod (I'm 43 with a family, my wife wouldn't
appreciate radical sound). I realize 'm going to get some sound increase
and tone change with he K&N and any performance exhaust system, just trying
to keep that to a minimum.
I've looked into programmers and aftermarket ECM chips, but they appear to
generally improve performance, not mileage, so I've set those aside for now.
I've also toyed with the idea of changing the final drive ratio. The rear
end is a Dana full-floating axle with locking differential (factory stock),
if anyone knows how big a job it is to change the gears, I might consider
swapping gears when switching between towing and non-towing jobs. I looked
at aftermarket Over/Underdrive auxilliary transmissions, but they're $3,000
and up, and the payback is really long.
Replacing the entire vehicle with a Geo Metro (or any other economy car that
can't carry 3000 pounds or tow 8,000) is not an option. This is a working
truck and payload requirements apply.
1993 GMC 2500 Suburban, 8,600 GVWR
5.7L (350cid) TBI
4L80E transmission, 3.73:1 final gears
93 GMC 2500 Suburban, 78K miles
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