Got a 4.3L V6? Use E85 !

arkenzo · December 18, 2014

Don't buy a CAI or one of those eBay chips to make your car faster, run E85! I've been using 91 octane from Chevron for a little over a year now and finally made the switch to E85, the performance I got from simply running E85 was more than I've ever gotten from running a CAI or SRI on a naturally aspirated engine.

Yes it's that good.

Placebo? Doubt it. Not sensitive to that stuff...

So give it a shot! Try it out and report back!!

SouthernSilveradoGuy85 · December 18, 2014

I've wanted to try E85 in my 5.3, but there isn't any stations that sell it anywhere near me.

arkenzo · December 18, 2014

I've wanted to try E85 in my 5.3, but there isn't any stations that sell it anywhere near me.

That's a bummer, I work in Long Beach and used http://propelfuels.com/ to find the nearest station with E85, found the closet one ( 5 miles from work ) on PCH in Wilmington. Nearest station with E85 from home ( Whittier ) is La Mirada and Norwalk, which is about 10-15 miles away. It's a mission just to get the fuel, but worth it if it isn't too much of an inconvenience.

SouthernSilveradoGuy85 · December 18, 2014

That's a bummer, I work in Long Beach and used http://propelfuels.com/ to find the nearest station with E85, found the closet one ( 5 miles from work ) on PCH in Wilmington. Nearest station with E85 from home ( Whittier ) is La Mirada and Norwalk, which is about 10-15 miles away. It's a mission just to get the fuel, but worth it if it isn't too much of an inconvenience.

Well the closest one is 50 miles away so that's a no go for me, at least until they put some closer.

Brian S. · December 18, 2014

I have burned several tanks of E85, it's readily available in the Midwest because we grow a ton of corn here.

It bumps hp from 285>>297, and torque from 305>>>330 on the 4.3l, which is a lot more benefit than you could get from a CAI. You'll buy 20-30% more gas, but at the $2.00-$2.50 a gallon it costs these days at least it's not such a bad deal to get 13mpg in exchange for the extra kick in the throttle.

(and you know your fuel money stays in America and employs Americans, helps wipe out our dependence on foreign oil, and is renewable)

About the only downside of the stuff is it's subsidized, but gas is indirectly as well by very low taxes.

Colossus · December 18, 2014

Not dependant upon foreign oil out here. The oil we pump into our cars here in the west and mid-west comes from the good ol USofA. And yup, I do run a few tanks of E85 a year in my flex-fuel car with the GM 3.6L in it, and it does make a noticable difference. Probably not as much as it does on the trucks though.

Chris · December 18, 2014

Not dependant upon foreign oil out here. The oil we pump into our cars here in the west and mid-west comes from the good ol USofA. And yup, I do run a few tanks of E85 a year in my flex-fuel car with the GM 3.6L in it, and it does make a noticable difference. Probably not as much as it does on the trucks though.

Enjoy that sweet Kern crude. Cant use the oil we produce here. It is too dirty and thick as molasses.

Silva · December 18, 2014

Now I really want to try it. I work in downtown L.A. so I'd have to go a little out of my way to get to a station. I've had my '14 GMC 4.3L for about a month, only filled up 2 tanks since delivery.

Would be interesting to see if there is any difference in power so early in the life of the engine.

Thanks for the update @arkenzo.

Fire2968 · December 19, 2014

Curious as to why you guys were running 89/91. Performance only? MPG suffers and higher cost also though correct?

SouthernSilveradoGuy85 · December 19, 2014

Curious as to why you guys were running 89/91. Performance only? MPG suffers and higher cost also though correct?

My understanding with the 89 and up octane is that if the engine is designed for 87 then running higher octane won't help it any. I say run what the engine is designed for. Of course if it's tuned or is forced induction then that's different.

Fire2968 · December 19, 2014

My understanding with the 89 and up octane is that if the engine is designed for 87 then running higher octane won't help it any. I say run what the engine is designed for. Of course if it's tuned or is forced induction then that's different.

Mine as well, which is why I'm curious. Unless you gents have your trucks chipped or tuned?

redwngr · December 19, 2014

My understanding with the 89 and up octane is that if the engine is designed for 87 then running higher octane won't help it any. I say run what the engine is designed for. Of course if it's tuned or is forced induction then that's different.

GM has fuel sensing and changes the tuning of the 2014 5.3L when it detects the E85.

There are GM published figures for the higher horsepower levels for the 5.3. I have never seen published numbers for the V6 (so don't know if it has dual tuning or if it is placebo effect)

For the 2014 5.3L these are in the Sierra brochure:

355Hp @5600rpm on 87 octane, 380HP @5600rpm on E85

383ft-lb@4100 on 87, 416 ft-lb @4100 on E85

for the V6: 285hp@5300; 305ft-lb@3900;

In the 2015 brochure, there is no mention of increased HP with E85.

For 2015, Flexfuel capability is std on V6, OPTIONAL ON 5.3L, and still not available on 6.2L.

KARNUT · December 19, 2014

GM has fuel sensing and changes the tuning of the 2014 5.3L when it detects the E85.

There are GM published figures for the higher horsepower levels for the 5.3. I have never seen published numbers for the V6 (so don't know if it has dual tuning or if it is placebo effect)

For the 2014 5.3L these are in the Sierra brochure:

355Hp @5600rpm on 87 octane, 380HP @5600rpm on E85

383ft-lb@4100 on 87, 416 ft-lb @4100 on E85

for the V6: 285hp@5300; 305ft-lb@3900;

In the 2015 brochure, there is no mention of increased HP with E85.

For 2015, Flexfuel capability is std on V6, OPTIONAL ON 5.3L, and still not available on 6.2L.

One of the Mags. showed a 3 tenth 1/4 mile gain with the 4.3 on E85 to 15.7 from 16.

SouthernSilveradoGuy85 · December 19, 2014

GM has fuel sensing and changes the tuning of the 2014 5.3L when it detects the E85.

There are GM published figures for the higher horsepower levels for the 5.3. I have never seen published numbers for the V6 (so don't know if it has dual tuning or if it is placebo effect)

For the 2014 5.3L these are in the Sierra brochure:

355Hp @5600rpm on 87 octane, 380HP @5600rpm on E85

383ft-lb@4100 on 87, 416 ft-lb @4100 on E85

for the V6: 285hp@5300; 305ft-lb@3900;

In the 2015 brochure, there is no mention of increased HP with E85.

For 2015, Flexfuel capability is std on V6, OPTIONAL ON 5.3L, and still not available on 6.2L.

I'm not talking about E85. I'm talking about regular 87-91 octane. My 5.3 is designed for 87 and E85, so if I filled up with 89 or 91 octane then there won't be any difference in performance. On the other hand, if an engine is designed (or after tune) for 89 or 91 and you put in 87 I believe it will lower the performance from what I've read. So all in all, just put in what the engine is designed run on. It's that simple.