E-85 gas question for 5.3 eco tech

[Tom's LTZ]

Just wondering if anyone is using the E85 gas in their 5.3 eco tech engine. According to the owners manual it shows about a 25hp increase over regular and about the same bump in torque. MPG shows not as good but here in Michigan its 40 cents per gallon cheaper. Thanks

[jj46]

I ran a few tanks through. Interestingly, when I run regular 87 octane (10% ethanol) and hook a scan-tool, the computer reports 9.2-9.6% alcohol in the fuel... (pretty accurate!). When I ran full tanks of E-85, the first tank showed 52% alcohol, and the second tank showed 60%. (Yes, I ran the tank nearly empty and did complete fills with E-85) So, my guess is, they ramp up the horsepower very slowly... you'd need to run several tanks before the computer really calibrates and gives you the best numbers.

 

I can't buy E-85 cheap enough here in MN to make it worth it... I'm back on regular.

[fondupot]

It also states in the manual that you shouldn't flip flop between regular gas (E10) and E85. I would assume it confuses the computer too much going from different octane rated gas between too frequently.

[Tom's LTZ]

Here in Michigan we have Meijer gas stations that always have it, not sure how popular it is though. When regular gas prices went up to the $3.75 range or more the price of E85 was more of a savings. Of course the bad news about E85 gas is costing us more for food now, thanks to the boys in Washington for that one!

[MikeNH]

I've been running E85 exclusively for most of the past year and it's almost always Meijer. There's a couple other brands in Ann Arbor that have it that I'll use if I need gas when I'm out that way though. No issues other than crappy range. For me I've calculated it needs to be 70-75 cents cheaper for it to be cost effective and since the tune I have to use premium or E85 so E85 is usually the better deal when you do cost per mile. Only times I haven't are when I take longer trips- up to St. Ignace for the car show in June and trips back east over the summer and coming up for Christmas.

[crushNchowda]

Barely any stations in. Ma carry it or I'd be using it exclusively

[dagwood2001]

Barely any stations in. Ma carry it or I'd be using it exclusively

 

Same in PA. Closest station is 30 miles away. They pretty much negates it being worth it right there.

[Crooks]

I don't trust the quality of e85 from station to station. It degrades quick sitting in their tanks. I would also have my truck tuned for e85 if that's what I was running.

[crushNchowda]

I don't trust the quality of e85 from station to station. It degrades quick sitting in their tanks. I would also have my truck tuned for e85 if that's what I was running.

If the manual states that it can be used and it also states there's an increase in HP, believe me it is fine. GM has 100,000 mile powertrain warranty and they want to avoid honoring it if they don't have to lol!

 

I would recommend a tune anyhow to sort out the sloppy characteristics of the tranny and I imagine a bone stock truck w/ a 93 octane tune from a legit dyno tuner would net 25-35whp legitimately. These trucks typically run pig rich from the factory, pull timing all over the place and add torque mgmt as well around shift points. A tune would do wonders for this truck, I can't wait to get mine done to be honest, just looking for the right place.

[jj46]

If the manual states that it can be used and it also states there's an increase in HP, believe me it is fine. GM has 100,000 mile powertrain warranty and they want to avoid honoring it if they don't have to lol!

 

I would recommend a tune anyhow to sort out the sloppy characteristics of the tranny and I imagine a bone stock truck w/ a 93 octane tune from a legit dyno tuner would net 25-35whp legitimately. These trucks typically run pig rich from the factory, pull timing all over the place and add torque mgmt as well around shift points. A tune would do wonders for this truck, I can't wait to get mine done to be honest, just looking for the right place.

 

Yep, they go ultra-conservative. And they have to, given all of the variables of how the truck will be driven, climate, altitude, crappy fuel, loaded/unloaded, etc.

[Tom's LTZ]

Thanks to all for the coments about the E85. Since the truck is designed for it I will give it a try. How about performance with 89 or 93 octane gas, any better than the 87? I know with the Ford Turbos they suggest using premium gas for best mileage and performance.....I only have 900 miles on my truck but I really like it, better ride than the Ford and seems like higher quality

[crushNchowda]

Thanks to all for the coments about the E85. Since the truck is designed for it I will give it a try. How about performance with 89 or 93 octane gas, any better than the 87? I know with the Ford Turbos they suggest using premium gas for best mileage and performance.....I only have 900 miles on my truck but I really like it, better ride than the Ford and seems like higher quality

In my experience GM smallblock V8's like the 93 octane fuel. I have seen a gain of about .3-.5mpg vs. 87, and a small SOTP difference in power. Now again, tuned exclusively for 93 it'll be a different animal entirely. I truly believe crank HP would be near 400 w/ tune alone.