What type gas do you use? 87? 89? 92?

Silverado-Hareek · March 25, 2015

I use 89 octane at the advice of Blackbear tuning. They recommend at minimum using 89 octane even on STOCK tuning (for the 5.3 and 4.3). 6.2 motors should be using a minimum of 91.

Ditto on all of this. 89 from Shell (top tier gas) for me.

Silverado-Hareek · March 25, 2015

It won't get me any better fuel economy and certainly costs me more, all true... but has better additives and runs cooler. It's worth the extra $$$ to run cooler when towing to me.

Higher octane gas does not have more additives. Additives will vary between brands of gas, but not octane levels within the same brand. For example, Shell 87, 89, and 93 all have the same amount of additives in the fuel. The difference is the octane rating between the three which can affect engine performance as lower octane is more likely to produce engine knock due to the high compression ratios of these engines. Engine knock, whether you can hear it or not, will cause the engine and computer to compensate for the knock which reduces horse power and fuel economy. So yes you should use higher octane gas when towing but not because it runs cooler or has more additives, but because you get better performance out of your engine since the fuel is less likely to cause engine knock. As Fondupot pointed out, per Black Bear Performance, they detect engine knock on 87 in these trucks and reccomend a minimum of 89 on even a stock tuning because of the high compression ratio of these engines. Check out Black Bear's FAQ's here: http://www.blackbearperformance.com/faqs.asp

Getting back to additives, they will vary between brands. A top tier brand like Shell will have more cleaning additives than a non top tier brand like say Sunoco. For more info on Top Tier gas go here: http://www.toptiergas.com/

05cyclone · March 25, 2015

I run 93 in mine.

Hunter11 · March 25, 2015

My wife drives a 2014 Silverado 1500 with the 5.3 and after reading this post last night I asked her what octane she has been running. She was use to running Mobile or Exxon 89 octane with her old Dodge Hemi truck she has been running that in her Silverado since new. I told her to stick with that.

crafferty · March 25, 2015

My 2014 Silverado 1500 has the 6.2L so I only run premium gasoline. I usually fill up at either Sam's Club, Jet-Pep or Raceway as they have the lowest price gas in town. 9/10 I fill up at Sam's Club since it is closest to my work and usually the cheapest of the three. City I get about 11-13mpg (lots of stop and go) and highway I see between 18-21mpg. Even with "Top Tier" gas my numbers stay the same and my engine oil looks the same when it comes out. I personally don't believe purchasing gas from Shell and other "Top Tier" vendors is worth the extra money as long as you take care of your truck and perform regular maintenance.

Newm · March 25, 2015

91 ethanol free for my 6.2

Lucky for me I have two choices close to home for ethanol free premium.

crafferty · March 25, 2015

91 ethanol free for my 6.2

Lucky for me I have two choices close to home for ethanol free premium.

What does that run per gallon? In my area its about $3.00/gallon currently.

Spurshot · March 25, 2015

So, all this talk about octane and fuel economy stirs some thoughts ...

1) Octane rating has nothing directly to do with the amount of energy per gallon

2) Octane is simply a "knock" rating. A measure of the fuel's ability to resist knock.

3) High octane ("premium") fuels typically have lower BTU/gal ratings than "regular" gasoline

Conservative driving (low throttle, no heavy loads, etc, i.e. low BMEP) might benefit better fuel economy by using the higher BTU content of "regular".

Edited March 26, 2015 by spurshot

Retired Bob · March 26, 2015

" A top tier brand like Shell will have more cleaning additives than a non top tier brand like say Sunoco." Being curious about the value of top tier gas in our DI engines (like gas not cleaning the valves) I contacted Sunoco and asked why they were not top tier - they said they also exceed the amount of additives required by the government (as is required by all top tier gas brands):

Sunoco fuels significantly exceed U.S. Environmental Protection Agency (EPA) gasoline detergency standards. All grades of Sunoco fuel contain the same level of detergent.
In addition to government-mandated detergency tests, Sunoco fuels are subject to additional testing by an independent, third-party lab to further ensure their quality.
Sunoco fuels contain other additives such as corrosion inhibitors and antioxidants, which help to ensure fuel quality. They also promote a longer “shelf life”, which means the fuel will last longer in between uses.
and the list goes on :-)

Plus Sunoco has been the NASCAR fuel for year - does that mean anything to us?. But another thing I believe is important is to get fresh fuel - some smaller top tier stations may have a low turn over in sales and the gas sits in their tanks maybe longer than it should - accumulates more condensation too. Ever seen a Sunoco that was not crowded?

I'm not selling Sunoco, I contacted them just to see why they were not listed as top tier - they didn't seem to think there was any reason to pay for the designation (cost about $20k or so to get tested by the top tier folks).

So, I believe Sunoco is probably just as good as a top tier brand, or at least an ok fuel to use in out DI engines. Plus they sell 87, 89, 91 and 93 octanes - most other stations only sell 3 levels - if that makes any difference :-)

POS VETT · March 26, 2015

Premium/high-octane gasoline has the same energy content as the regular/low-octane gasoline. E85 is a different story; it has much higher octane rating but less energy content. There is no correlation between the octane rating and the energy content. The high alcohol content shifts the fuel characteristics toward the alcohol.

Newm · March 26, 2015

What does that run per gallon? In my area its about $3.00/gallon currently.

Seems like it has bounced between $2.50 and $2.70 a gallon lately.

crafferty · March 26, 2015

Seems like it has bounced between $2.50 and $2.70 a gallon lately.

Damn at $2.50 a gallon that would only be about 5-10 cents more in my area. At that price I would run it all day long.

Isriam · March 26, 2015

octane doesnt affect your mpg, the computer mapping/timing will and thats where people see the difference.

Ridersfan · March 26, 2015

Higher octane gas does not have more additives. Additives will vary between brands of gas, but not octane levels within the same brand. For example, Shell 87, 89, and 93 all have the same amount of additives in the fuel. The difference is the octane rating between the three which can affect engine performance as lower octane is more likely to produce engine knock due to the high compression ratios of these engines. Engine knock, whether you can hear it or not, will cause the engine and computer to compensate for the knock which reduces horse power and fuel economy. So yes you should use higher octane gas when towing but not because it runs cooler or has more additives, but because you get better performance out of your engine since the fuel is less likely to cause engine knock. As Fondupot pointed out, per Black Bear Performance, they detect engine knock on 87 in these trucks and reccomend a minimum of 89 on even a stock tuning because of the high compression ratio of these engines. Check out Black Bear's FAQ's here: http://www.blackbearperformance.com/faqs.asp

Getting back to additives, they will vary between brands. A top tier brand like Shell will have more cleaning additives than a non top tier brand like say Sunoco. For more info on Top Tier gas go here: http://www.toptiergas.com/

Premium fuel, in Canada, has a higher octane and more additives. It's more than just higher octane... at a quality place... the cheapo places, that may well be the case. I don't have the background to explain why or what or how... but my truck runs cooler towing a 6000 pound camper when burning petro-canada premium 91 octane gas vs a cheap 87 from fasgas or walmart. Argue against it if you want, I really don't care... I've seen it, it matters to me, and that's what I care about, more so than arguing over it.