another mpg question
02-23-2011, 12:49 AM
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another mpg question
so the wife drives a 2000 tahoe z71 with a 5.7. it has k&n intake, 3" flowmaster cat back. we have owned it about 4 months now. first checked mpg, was getting 10.4 city all stock. now with mods getting 9.3 mpg. this is with my wife driving. I would think it would be better than that. we really love every thing about it but the mileage. I know its no econo box, but my 97 5.7 2wd silverado gets 16-17mpg in town and thats with me driving ;-) any ideas? it also only has about 3k on complete tune up. I also wouldn't be apposed to ditching all the 4wd parts to save gas if it would be enough of a difference. 2wd's are hard to come by around here. Thanks
02-23-2011, 07:14 AM
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Is this a 5.7 Swap? If not then it should be 5.3 ... other than that the only other thing I can suggest is tuning. You threw on a bunch of mods, without a tune you PCM has no idea WTF is going on. All it knows is youre getting way more air and fuel than its prgrammed for.
02-23-2011, 07:31 AM
#3
Any extra weight you can shed always helps. Tires with low rolling resistance and properly inflated help. A general tune up, timing, and compression check (since it is a 2000) would be a good start. If mechanically sound, you would also probably benefit from having a tune done on it (pcm) as there are a number of things to optimize to add both power and efficiency. There are a number of mail order or local tuner solutions (including sponsors on right) some offering lifetime updates. cheers
02-23-2011, 11:52 AM
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Is this a 5.7 Swap? If not then it should be 5.3 ... other than that the only other thing I can suggest is tuning. You threw on a bunch of mods, without a tune you PCM has no idea WTF is going on. All it knows is youre getting way more air and fuel than its prgrammed for.
02-23-2011, 07:25 PM
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edit:
you may also want to look into the 0411 pcm swap. It is more tuneable, allows a higher rev limit, and has a few other benefits.
Last edited by offroadrider12; 02-23-2011 at 07:56 PM.
02-23-2011, 07:25 PM
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Oh that does change things a bit... I thought they quit that setup in 99. In that case you may need to find someone with the old LS1 edit. You might have a good chance at a tune then. Im not sure if HPT or EFi offer tunning for that PCM honestly.
