TOPIC: 2018 GMC Sierra 1500 6.2L V8 - Starting from scratch

Great job Andrew! You have worked hard for your truck and the power is going to be unleashed! Enjoy and be carefull!

Now that we’re halfway through the first quarter of this New Year, I’m wondering if you might have any updates on this Truck, Andrew. How’d the EFIE and MAP modifier installs go? What’s your mileage at now?

Howdy! Pardon my hiatus! Lots of personal issues to attend. But, things are settling down and I can focus on more fun endeavors!!

I've been clocking between 13-14.0 mpg fairly consistently. I just put some Snake Oil in the rear differential, today. I haven't put any in the transmission yet, because you need a special tool to even check the fluid level. Stupid. I'll have the fluid changed and see if they'll add it for me.

As far as the EFIE/MAP, I still haven't applied either. I think I'm going to RE-groove the throttle body first. I was looking at the manual again and realized I grooved it slightly wrong. I don't think I put enough of an angle to the groove. I pretty much followed the throttle plate straight down (in the way Ron did in the early grooves). I think I can do a better, more efficient groove. I'll consult with Ron first.

Also, I just found out the computer was never recalibrated to account for the bigger tires. The speedometer is 10% off! So, the actual mileage is likely 10% better than I'm indicating. So, that is good news!

I'm thinking about having it tuned prior to the EFIE/MAP install? A professional tune would correct the tire discrepancy, cold air intake and cat back exhaust mods according to the guys at the performance shop.

So, that is the latest. More frequent updates forthcoming.

You Should re-flash the computer to account for the tire size, but before you go full "performance tune", check this video out and poke around on this guy's channel:



I'd wager that some aerodynamic mods will be more effective at putting the engine's power to the road, and saving more fuel in the process.