swathdiver
Full Access Member
Dave, that knocking and pinging is why your #4 piston fell apart. It costs more money, not less, to run the lower octane fuels. Run three tanks of each and note the difference in fuel economy.
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
High desert as in apple valley?! Victorville?! Didn’t know there were any other members so close hahaI hope you don't plan on scrimping on oil, too!
- High desert. We have two locations and both qualify as high desert, I believe. As others have said, you've got a high priced vehicle. Not wise to go cheap on its fuel. I not only run 91, but only Top Tier. Not hard to find, just look for it.
![]()
Thanks Lalo.I tried running regular in my 2015 Denali you definitely feel the difference only put in premium because of the higher octane , when you use the loweroctane fuel your knock sensors will tell the ECM to retart the timing also your car is also drive by wire so it will protect itself from detention but you won't have the full power of the 6.2 ...which was a selling point for me , I would stick to the premium on the 6.2 ....
you're only saving about $4 every full up and that's if u fill from empty. even if u fill up every week that's probably less than $20 a month in difference which I hope since you have a basically brand new truck isn't a big deal
If the gas your using is not correct, your engine will let you know by spark knock or poor performance. If you notice on the pump, their method of determining OCTANE rating is of + or - 2 which is to be considered. Sometimes I wonder just exactly what your paying for, it is what it is. My 5.7 runs fine with the 87 octane with no lag in performance or spark knock. JMHO.
David g............![]()
Consider it this way JC:
87 octane is $2.39 a gallon and let's say 26 gallons to fill up. That's $62.14 and 87 in our mythical truck returns 14 mpg for a range of 364 miles. That's $.17 cents a mile.
93 octane is $3.09 a gallon and let's say 26 gallons to fill up. That's $80.34 and 93 in our mythical truck returns 16 mpg for a range of 416 miles. That's $.193 cents a mile.
Not much difference in price when looked at this way, big difference in performance and in the care and feeding of the motor.
It costs me (with a bad cat) about $.24 cents a mile to run 93 and $.19 cents a mile to run E85 on average for both as fuel prices are ever changing.
@BlackBearPerf @JennaBear @JustinI am not saying you are wrong, far from it. However not everyone gets a tangible increase in fuel efficiency when going with higher octane. If people are not experiencing detonation or other maladies from lower octane, your aforementioned example is not necessarily accurate.
For high performance engines I do only run 93 or even 94 if I can find it. Heck on occasion, I'd have jet fuel grade gas regardless of cost if performance was demanded, fuel efficiency be damned.
Still, with regular demands on typical driving scenarios, I am not sure any of out 6.2's really benefit that much between low and medium grade fuel.
Lastly, where I live in S FL, price differences can be greater than $0.70 per gallon. Heck there was a $1.02 difference between regular 87 in one part of the county vs. another for 87 grade.
I am not even sure what the difference was for premium, as I was in shock at the difference for the same grade.
`
It is almost laughable that someone owning a truck that expensive would put rat piss gas in it! In short, you could easily grenade your high performance, high COMPRESSION engine with the wrong octane gas!
http://www.hotrod.com/articles/eliminating-detonation-pre-ignition/
Here’s some nice pics....View attachment 190849View attachment 190850
Ironically here in California, shell has excellent gas. Which is what I buy here in big bear, but unfortunately 91 octane which I run my 6.0 on, is 3.55 a gallon. Ski town jacks up prices. But at Costco down off the mountain, which has good quality gas I’m spending I think right around 3 a gallon. If I have rewards points built up from my groceries, I can go to chevron and pay just under 3 a gallon for 91 octane, that isn’t that often though. It’s true, you get what you pay for, cheap companies cheapo gas and you’ll get ****.... lolJC, I've been proving this point for thirty years from Toyota Corollas to my new to me Yukon. I'm just north of you and the spread between high test and low is shrinking again, it used to be just .10 cents per grade difference not so long ago. Today, at a top tier Mobil station nearby in Jensen Beach, the spread is $.60 cents, $3.15 for 93. Last month it was $2.87 for a week or so. Even E85 went up from last week, about twenty cents a gallon.
As I've said before, y'all have to work out which Top Tier fuel works best in your auto and where to buy it at the best price. I've seen several mpg differences between Top Tier 93 among stations, my Montanas run awful on Shell's 93 compared with Sunoco and run even better on Mobil and Chevron. My truck is bearing that out too.
And, last time I checked the lower octane fuels do not have the additives that contribute to keeping the fuel system clean, that alone is worth the cost to me. A great many of the driveability problem posts are because of folks running that cheap gas. One gets what they pay for, seemingly anyway, it costs more to run cheap gas than good gas.