87 octane vs 91 octane

[HACK BLOCK]

Wait.... You get 4 choices!?

sunoco is the only 1 I can think of off the top of my head that sells 91 in ny. all other stations are 87, 89, 93. and if the pump has diesel that's 5 choices!!!!!!

 

[PG01]

sunoco is the only 1 I can think of off the top of my head that sells 91 in ny. all other stations are 87, 89, 93. and if the pump has diesel that's 5 choices!!!!!!

The sunoco down the street from that one, ~2 miles away, only has the 3 but thats a pretty new station too, the one in the pic has been there for years....

 

[HACK BLOCK]

the one I go to has 4 also

 

[dbbd1]

Wait.... You get 4 choices!?

Yeah, I know! I'd love some 93.

 

[Miami-Dade]

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............

agreed 110% I've never had any issue running 87 in my 5.7 Hemi's!

When I bought my brand new 1996 Impala SS with the 5.7 I used nothing but 87 in it ...It ran perfectly fine until I sold it with 180K miles..I never ever should have sold that awesome car..I also used 87 in several Cadillac's, GTO's with the 400 ,V8 Caprices,Police Interceptor,5.4 Expedition and Town Car..Put 300K miles on a few of those..I had long commute to work and do not fly so drive everywhere..I had zero issues running plain old 87 regular.

On my 5.3 Tahoe I get between 24-25 MPG out on the highway and around 15 locally [which is usually gridlock the bulk of the time] with the a/c system always on as I just set it and forget it..If I were to use 89 or 93 I know I would not do any better so it would be a total waste for me..I have yet to see anyone else with a 5.3 put in anything other then 87.

Last week on the Florida Turnpike several troopers came in to the Snapper Creek Service Plaza [their barracks are right there] to fill up their 5.7 Hemi Chargers..They all put in 87..My county also has several 2015 plus Yukon Denali's with the 6.2 for undercover and they use 87 in them.

I only use 87 Exxon-Mobil as I find those stations are well maintained throughout the whole country.

For some people I think using 89 or 93 is just a placebo effect and nothing else..All that is just IMHO..To each their own.

 

[swathdiver]

My challenge to you Gary is to run 3 tanks of Exxon-Mobil 93 in your Tahoe and note the difference or lack thereof in mileage. In my experience you'll gain at least 2 mpg and probably more.

Those government employees are putting in their government cars what the government tells them to, the lowest bidder's gas.

 

[Miami-Dade]

My challenge to you Gary is to run 3 tanks of Exxon-Mobil 93 in your Tahoe and note the difference or lack thereof in mileage. In my experience you'll gain at least 2 mpg and probably more.

Those government employees are putting in their government cars what the government tells them to, the lowest bidder's gas.

On my next long trip I will James..That will probably be in March or May..Right now traffic is so bad in Miami Beach,Miami Dade and even Broward that I could run in V4 mode 90% of the time.

 

[Vector]

Well I just checked and Costco premium is 93 octane and is $2.84 per gallon. While certainly more than the 87 octane regular at $2.46 pg, at least it is $0.15 - 0.20 per gallon cheaper than what most premium is going for in S. Fl
Plus if you have the Costco Visa, you get 4% cash back on every fill up.

 

[minytrker]

When I bought my brand new 1996 Impala SS with the 5.7 I used nothing but 87 in it ...It ran perfectly fine until I sold it with 180K miles..I never ever should have sold that awesome car..I also used 87 in several Cadillac's, GTO's with the 400 ,V8 Caprices,Police Interceptor,5.4 Expedition and Town Car..Put 300K miles on a few of those..I had long commute to work and do not fly so drive everywhere..I had zero issues running plain old 87 regular.

On my 5.3 Tahoe I get between 24-25 MPG out on the highway and around 15 locally [which is usually gridlock the bulk of the time] with the a/c system always on as I just set it and forget it..If I were to use 89 or 93 I know I would not do any better so it would be a total waste for me..I have yet to see anyone else with a 5.3 put in anything other then 87.

Last week on the Florida Turnpike several troopers came in to the Snapper Creek Service Plaza [their barracks are right there] to fill up their 5.7 Hemi Chargers..They all put in 87..My county also has several 2015 plus Yukon Denali's with the 6.2 for undercover and they use 87 in them.

I only use 87 Exxon-Mobil as I find those stations are well maintained throughout the whole country.

For some people I think using 89 or 93 is just a placebo effect and nothing else..All that is just IMHO..To each their own.

I have been tuning 15+ years now. When I go to tune a truck or suv I can tell 99% of the time if they have 87 oct fuel in the first dyno pull or the first few miles of driving if its not on the dyno. Will they run and drive on 87, yes of course but they will have knock retard like crazy and the ecm is pulling timing and eventually forcing it to run on the low octane timing table. It basically de-tunes itself to in order to run on the crappy gas.

 

[sickk23]

We only have 91 here. Would love some 93 in summer when temps are 100. In my burb I just pump 88 (mid grade). But in my wife’s Hemi I’ll put premium, and the fuel door said “premium required” on my bimmer I had before the burb.

 

[JonnyTahoe]

Here’s some nice pics....View attachment 190849View attachment 190850

We have 102 Racing fuel at some gas stations in the metro area.

 

[dbbd1]

We have 102 Racing fuel at some gas stations in the metro area.

View attachment 191730

Dang!...

 

[Scottydoggs]

i can get 101 local. its also 11 bucks a gallon, no thanks.

 

[HACK BLOCK]

if the manual says put 91/93 then you should. yea u can run 87 but you'll probably lose performance. there is always gonna be somebody that says they put 87 and it runs fine. I never really understood why someone would buy a car that needs 91/93 and complain about it. I mean would you put 87 in a Ferrari cause 91/93 cost more?

 

[cardude2000]

The engine will adjust but you’ll lose power and mpg. Put in the correct gas.

Don’t worry about engine temps. That myth has been long busted. (Most folks mix up racing fuel and pump fuel which use different methods of boosting octane).


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[GTNator]

We have 102 Racing fuel at some gas stations in the metro area.

View attachment 191730

What metro area is that? And why do they offer racing fuel as a regular product there? Is it close to a popular track?


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[Rocket Man]

I agree that you should run what your owners manual says to run. If it's tuned to run on 87, you won't see much difference in mpg running 91 and you'll be wasting money. If its tuned to run 91 or has high compression and you run 87 you risk detonation or ping and damage. The tuning tables have flexibility but that's designed for differences in brands, not necessarily different octanes. I had the availability of 2 different tunes from BB on my Autocal, 87 and 91. I ran both for several tanks and saw about 1-2 mpg difference which wasn't worth the added cost. But now that I installed the Whipple I have no choice but to run 91+ and my tune is set up for it.

 

[Fless]

Regular octane at high altitude (like Denver) is 85. Less oxygen in the air tends to effectively lower the compression ratio, from what I've heard. I usually run at least 87 anyway, higher when towing.

It would be interesting to actively monitor ignition timing to see if the knock sensors cause timing retardation when running 85. Is there a valid way to do that?

 

[noob]

I run 93 octane almost exclusively. I notice about a 2-3 mpg drop and decreased acceleration on 87 in the past, so I see it as a wash.


Edit: my car is a 6.2 liter escalade that says premium fuel only. Hence your mileage my vary on the 5.3L.

 

[swathdiver]

It would be interesting to actively monitor ignition timing to see if the knock sensors cause timing retardation when running 85. Is there a valid way to do that?

Sure, a good scan tool can see that in real time. The Tech2 can certainly see that.