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**Boog** · 02-27-2010, 10:33 AM

2000 GMC Sierra excab Z71
5.3 auto OD, 3.73
285/75/16 tires

I've only had it on one good trip since I've had it and I wasn't impressed with the mileage. 800 miles and 15.5 mpg running mostly 70-75. Certainly could have been worse but I expected more out of it. Tires are oversized but the speedo reads correct so that's been taken care of.
Now the previous owner towed a small 5th wheel trailer with it for a while and I suspect he may have had a towing tune installed in it. I don't know how to check to see if it's been changed though.

02-27-2010, 10:33 AM	#27
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,030	Re: Fuel milage survey 2000 GMC Sierra excab Z71 5.3 auto OD, 3.73 285/75/16 tires I've only had it on one good trip since I've had it and I wasn't impressed with the mileage. 800 miles and 15.5 mpg running mostly 70-75. Certainly could have been worse but I expected more out of it. Tires are oversized but the speedo reads correct so that's been taken care of. Now the previous owner towed a small 5th wheel trailer with it for a while and I suspect he may have had a towing tune installed in it. I don't know how to check to see if it's been changed though. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross