swathdiver

Coasting down the hills and mountains is always good for mileage and can often offset the climb. Now let us know how she does on the return leg.

Thanks. Was wondering if your secondary tank was stock (2500) or added (1500).

Is your Suburban on a 1500 or 2500 chassis?

Drop them a glass of apple cider vinegar overnight.

Eventually, I think we've been given a reprieve for at least a little while.

With government regulations easing, automakers will surely go for cubic inches and torque. There's nothing wrong the L96 that a tune cannot cure. We're fortunate that the govment didn't legislate that motor out of existence too.

I went on Fuelly too the other day and took the average economy of every GMT900 SUV for all years. Average of averages the 5.3 equipped trucks average 14.37 MPG. Long or short, 4-speed or 6-speed didn't matter, they all averaged 14.3X mpg.

I was never a fan of Bridgestones but it is hard to argue against those that are on your truck. Michelin is probably better and they do offer low rolling resistance models. What size are you currently running? I took mine out tonight for some mileage tests, thought I had loaded the new tunes from BlackBear but didn't do it right, I think. Anyhow, at 70 she averaged 18.24 in 6th (five samples taken). One sample was taken in M5 at 70 for quite a ways and she averaged a rock solid 17.5 mpg. Without an inclination gauge it's tough to make sure we're flat and level. I'm thinking about calling up the LOAD and Torque Settings at the differing speeds and basing the numbers off them. When installing the tunes again, the prompts were slightly different this time so I think I did it right. However, it had rained and the roads are now wet which would skew the numbers so it'll have to wait another day.

That's a common misconception, such was not true. Time would have improved the design, mine was the ultimate "D" block which racers converted to gas for drag racing. They were essentially legislated out of existence and their successor was the 6.2 and 6.5 used in trucks which are still used by the military to this day. That LF9 got 24 mpg delivering pizzas all night (never shut off) and over 35 mpg on the highway. Most folks killed them with dirty oil and trying to spin the engine into the red all time.

I loved my 5.7 Diesel, it was in our '82 Olds Cutlass Supreme Brougham! Miss that car! Used to deliver pizzas in it and used to bracket race at the drags with it. If I had kept it longer, I was going to put a 200R4 and a 3.42 gear behind it and "tune" the injector pump for more power. The Buicks consumed all my attention then and we sold it to our lawn guy.

Why not stick with the Bridgestones?

Sounds like you're driving around with a locked up torque converter. Or a bad MAF sensor. If it was clogged cats it should have thrown a code. Have you checked your Long Term Fuel Trims? It's almost impossible to properly diagnose these trucks without a bi-directional scan tool. The Tech2 is too old for these but you can get the MDI with GDS software and put it on a laptop and see and check and test everything necessary to find the problem.

The 8.6" differential is the weak link in our drivetrains. Gotta keep clean fluid at the proper level in them (2.15 Quarts) and watch your weights when towing. Even then, guys who regularly tow at or near maximum capacity wind up needing new center sections or other parts. If this axle has problems again, consider the 9.5" AXN that bolts right up that was used on 2WD Avalanches and Escalades.

I'm not familiar with K2 but there should be internal BCM codes with regards to the AC. Now, is the engine a Duramax diesel or L96 gas? What happens if you gun it from a stop?

Me too! Almost an excel junkie, use it for all sorts of things, even drawing.