Black Bear Tune on my 2011 5.3L Tahoe

[MACHO]

2011Tahoe, yours and others positive results make total sense when going on long hwy trips. That's awesome. On the two trips we made to E. WA, we averaged 17-18 (pre-tune). I'm confident with the tune those numbers would increase on those same trips. Now if only we could get those kind of MPG's in town

 

[Jmat]

No prob bro. That's what I love about TYF. GM brethren helping each other out!

Right on Macho!

 

[MACHO]

UPDATE: ran 2 tanks of 92 chevron thru it

DIC ended at 14.3 avg mpg.

Got 665 miles out of two tanks. This puts my "real world" avg at 12.78 based upon a 26 gallon tank. However I'm sure the volume of gas used is skewed since when I filled it the second time (wife re-filled first tank so don't have those numbers) it only took 22.5 gallons.

Assuming the same gas usage of 22.5 gallons on both fill-ups that puts it more around the 14.7 range.

Update: with accurate numbers now

2 more tanks of 92 for a total of 47.2 gallons and 679 total miles. Quite a few remote starts.

= 14.5 mpg on 91+ tune. (14.9 DIC)

Will be going to stock TCM tune per Justin's recommendation and comparing.

 

[2011Tahoe]

Hmmm....will be interested to see the comparison to stock. To make you feel better I just took a trip from Chehalis, wa down I5 thru Portland and down the gorge to eastern Oregon. I ran a completely full tank of E85 thru it and the fuel mileage was horrible!!!! I knew it was not going to be as good but I did not think the Dic would read 14.2 !!! It sucked! Plus it was just about the same price as reg 87. Double fail!! It was smooth sailing with no wind, no traffic and only 1 stop, never took the cruise off 70mph. It was just me driving and I left at 6:30 pm. The only positive was the response seemed pretty crisp when getting on the hwy and performance did seem a little better. Guaranteed if I would have ran 87 reg it would have read atleast 19.5 because the conditions were great for max mpg's.

 

[MACHO]

Dang. Yeah from what I've read, e85 isn't necessarily a cost saver.

I didn't even know you could get e85 in WA.

 

[2011Tahoe]

I didn't even know you could get e85 in WA.

Yeah there are only 2 stations 1 in Chehalis and the other is on top of snoqualmie pass.

 

[tx tahoe z71]

E85, by simple chemistry, will use about 30% more fuel than E10 gasoline. Stoich for E85 is 9.76 vs. 14.08 for E10 93 octane. So if it is 30% cheaper, then it should be breakeven, if not, it will cost more to use.

However, E85 for forced induction is awesome, it's like running race gas (it's about 105 octane = more timing), is less prone to detonation (can safely run more timing without risking blowing things up), and burns cooler (due to water content) than 93. With my truck tuned for E85, it is a night and day difference and probably worth 50+rwhp. I have seen some cars and trucks gain 75-100rwhp running E85 (tuned for it, of course).

 

[JennaBear]

Seeing as how this is an 07+ thread, I feel the need to clarify for those who are running a supercharger.

Unless the vehicle is a 2002-2005 and has an actual alcohol sensor; the procedure that the ECM uses to determine ethanol content results in dangerous operation for 10-15 miles after every fill up. I would not recommend E85 for 06+ vehicles running a supercharger.

The only caveat, is if you are tuned to run E85 exclusively.

 

[MACHO]

Ok guys here's an updated comparison with the data on 2 tanks of gas thru it in each scenario:

12/4/12-- 91+ ECM TUNE/ CUSTOM TCM TUNE:

47.2 gallons
679 miles
14.9 mpg DIC
14.5 mpg real world


12/17/12-- 91+ ECM TUNE/ STOCK TCM (lots of remote starts):

766 miles
47.9 gal
16.6 mpg DIC
15.99 mpg real world

 

[Blazed]

So trans tune = worse mpg