I bought an 08 Tahoe Hbd last year with 50k on the clock and just found this site. I just bought a Volant intake/TB spacer and I plan on getting rid of the resonator already. I want to upgrade the nav/radio unit to a new one with Bluetooth too. Any other mods worth doing to get better mileage? Has anyone done upgraded ignition coil packs or an exhaust?

 

The hybrid is already good as delivered. No further tweaks can make it better.

 

I disagree, I have made a ton of tweaks(both performance and appearance) and most(but not all) have definitely improved the vehicle.

I installed the Volant intake @ approx. 75K miles and it certainly has improved the MPG, plus now it has a throaty sound under heavy acceleration.

When the Volant was installed I had the rest of the intake disassembled and given the once over, nothing major, just made sure everything was port/gasket matched and removed any large casting remnants, I believe this increased MPG ever so slightly.

I removed the resonator(33 pounds) and had the rest of the exhaust massaged, this also increased MPG slightly.

I had all of the fluids replaced with true highest quality %100 synthetics(IE not Mobil 1 which is not a true synthetic), I believe this helped the MPG slightly.

I replaced the stock crap Bridgestone tires with slightly narrower low rolling resistance Michelins, this was perhaps one of the best improvements, it rides like a totally different vehicle, 100% better and possibly increased MPG as well.

I removed the 3rd row seat to give me more room and subtract 100+ pounds(any weight removal will increase MPG)

Replaced the 12V Delco battery with a light weight Braille Battery(weighs 21 pounds as opposed to 39 for the Delco)

There's a bunch of other stuff I'm probably forgetting, I'm always tinkering with this vehicle.

I usually get bored with a car after a year or two but I still like this one, I bought it new in 2009 and have put all 110K miles on it, I plan on driving it until it gives me a major issue. I had it at the dealer not too long ago for a routine check up and the mechanic is confident it could go 250K+ miles without any major service.

PS, I'm at 110K miles on the original friction brake pads and they still have over 50% material left, I'm on the fence on whether to try to get 200K out of them or just be safe and replace them due to age.(disclaimer, I learned to drive on big trucks and letting the vehicle weight & engine do most of the braking)

 

I usually get 585-587 miles range on my trips. Did your improvement increased your range? We're you able to increase the top end to >100 mph?

 

I average 24-25 MPG and 550-575 miles per tank which is an amazing feat considering our gasoline quality in the Phoenix area is abysmal, they add up to 10% ethanol and 15%MTBE which kills MPG, also I honestly believe they add more Ethanol than the allowed 10% to increase their bottom line.
When I put 100% gasoline in I can get 27-28 MPG and over 600 miles per tank, there are only a few stations that sell 100% gasoline in Maricopa County and it's very expensive, they call it "Racing" gasoline even though it's just average 89 octane.
I calculate all of my mileage figures by hand, the trip computer on my Tahoe is overly optimistic sometimes.
My Tahoe like most is speed limited to about 99 MPH but it hits the speed limiter like a brick wall, I think it could probably go 125+ MPH easily, it's surprisingly smooth and steady at 99 MPH.
I thought about getting an interface to get into the computer, remove the speed limiter and experiment with some of the other parameters but I just haven't gotten around to it.