Quick99

87 Regular is fine as the owners manual states. You will notice a performance drop off.... But 91+ is better so get back to the rich stuff as soon as you can... Here in GA we get 93 octane for $0.60 a gallon more than regular, cant see a station owner running out at this price differential......

JNess

He is probably in Texas. The hurricane took out 2 of our main gas pipelines, so most of Texas is dealing with gas shortages.

I'm in DFW and just recently had to fill up with 87 octane, as mid and 93 were not available. I chose to just put in half a tank, hoping that I can fill up this weekend with 93, if the station gets a refill.

We likely deal with the many idiots that feel that 'premium' fuel is better fuel. So the high octane fuels were the first to be depleted.

It has gotten better, as there are no longer huge lines at the stations, you just have to deal with possible shortages.

JNess

Oh, and as to octane boosters.... Don't believe the claims on the bottle. Generally when it claims to raise octane by up to 5 points. It is usually something along the lines of 5 hundredths of a point.

So your 87 octane, with the booster, is like 87.05. It is a complete waste of money. One of the main ingredients is usually Toluene, and it can be purchased by the gallon at a home improvement center. You can get a much better boost in octane by mixing your own octane concoction. Do a google search, turbo people have been modifying their gas for years with home improvement store chemicals.

jdhommert

Maybe check other stations when you head out of town etc.

If you do have to run only 87, you'll be ok-just make sure to drive it slow and keep your foot out of it and don't let it lug either

WideVette

From an engineering aspect, running a lower octane fuel than recommended, will increase mpg, in fact significant enough to measure (10% + is very possible). The benefit does diminish according to how effective the electronics adjust for octane ratings. More advanced technology equates to lower impact.

Using Ford for example, a 90's Mustang with a recommendation of premium will result in better mpg, all other things equal, with lower octane. A newer model from 2015 will not see nearly the increased benefit.

This is the primary reason Ford was early to allow their performance vehicles, especially turbo's, to run safely on lower octane indefinitely. It does equate to a loss of performance but slight improvement in mpg which is of great consequence in the chase to meet CAFE.

It's in the burn of the octane. Proven science.

This is separate from the concern of lower octane and loss of either performance or protection. Not intended as a statement to either.

spinkick

Crazy. I have a chevy volt that when it runs on gas, seems to get better mileage from the recommended premium octane vs 87.

LDB

I assume this post is a joke. Nothing in it is correct. Even on trivial issues, while all of the various octane isomers do indeed burn, this post refers to “burn of the octane” meaning octane rating. Octane rating is a test, not a combustible substance.

C6_Racer_X

The only nugget of truth in there is that Ford actually did lower the octane requirement on some of their vehicles, and it was for fuel economy reasons. They have to run the "specified" fuel (what the owner's manual requires/suggests) for fuel economy tests.

For CAFE reasons, manufacturers want as many vehicles as possible to run on 87 (less ethanol in that blend, so MPG is increased.).

LT1 Z51

I've never worried about using 87 in a car that doesn't specify 91 or higher as long as I'm not driving aggressively (or at the track).

Most ECM/PCM's are pretty smart and catch lower octane quite quickly.

Personally, I think we should stop selling anything less than 89 octane. Economy should be 89, Regular should be 91, Mid-Grade should be 93, and Premium should be 95. This would line up with what Germany currently uses (in most of Europe "Regular" is 90-91 in our octane rating, they use a different octane rating so they call it "Super 95").

Mike Campbell

Look, I have some cheapie friends that use 87 octane in their Corvettes and do all the time and tell me, "It doesn't hurt the car at all!" I always say, "Really? Do you use drain oil too?" You know, in a "pinch".

VetteDrmr

Europe calculates their pump octane ratings differently than we do. EU 95 is equivalent to US 91, EU 98 = US 93. So we already match up fairly well. So EU 91 is roughly US 88; EU 90 = US 87.

Have a good one,
Mike

LDB

You are right about European octane postings being about 5 higher than ours. That’s because they post octane as determined by the “R” method, while we use (R+M)/2, and the “M” method gives numbers about 10 lower than the “R” method for the same fuel. You are also right that “regular” in Europe is mostly 94 or 95 by their “R” method, which makes it close to our 89 (R+M)/2 mid grade. What you may not realize is that there’s a logical explanation for why their fuel is a bit higher octane than ours. As a percentage of the crude oil barrel, US gasoline demand is much higher compared to Europe. That in turn means that European refineries can do a bit more cherry picking of the best and easiest gasoline components, while we must strain to maximize gasoline, thus including some lower quality components that the Europeans don’t normally include. We could turn those lower quality components into higher octane to match Europe, but you probably wouldn’t like the price.

LT1 Z51

I’m aware. Hence my comment “Super 95� is about 91 octane.

Maybe next time I bold that? It seems two posters corrected me when no correction was needed.

VetteDrmr

What drove my post was your implication that our 87 octane is lower in octane than the lowest in the EU, and that's not really the case. Gasoline on both sides of the pond are fairly equivalent.

Have a good one,
Mike

LDB

I didn’t correct you. I agreed with you on both of your points (the reason for the big offset being octane method, and your point that even after correcting for the method difference, European octane is slightly higher than US). I simply added a third point, namely, the explanation of why octane on average is slightly higher in Europe than in the US. That leaves me, like you, disagreeing with VetteDrmr who says US and Europe octane is essentially equal.

Yes VetteDrmr, there is general correspondence. But most European regular is 94 or 95, which corrects to 89 or 90 in our terms, so 2 or 3 higher than ours. Likewise, most of their premium is either 98 or 100, which corrects to 93 to 95 in our terms. Europe even sells some 101, which would correct to 96. So while the difference is not the 6-8 numbers of the raw values, even after correction, Europe is about 2 numbers higher than we are.

NSC5

The way octane numbers are "scaled" isn't very friendly to the general motoring public. Many think of it in terms similar to temperature where 87 versus 89 degrees isn't really perceptible (and within the measurement error of most thermometers) but 87 vs 89 octane can be very significant depending upon the engine.

With the dumbing down of America we probably need a letter system so auto makers can simply tell consumers to match a letter on the pump selection to the letter on your gas cap, D for 87 octane etc. It would help some with those who waste resources by choosing an octane level that provides no benefit for their vehicle or those who risk reduced performance, mileage, and engine damage by using too low of a grade.

LT1 Z51

Right, and in Europe they tend to not use the lowest grade (labeling it economy). So their "mid-grade" or "super" is regular.

Hence my comment on "Super 95" being close to 91 Octane (95 Octane under their system in Europe) being equivalent to "regular" gas. They have Super Plus (which I think is close to 93) and then an even higher one (usually 100 or 102 in their octane).

So in Europe they have 88, 90, 92, 94 (in our octanes) and most people use 90 or 92, 88 is not even sold at all stations and in Italy, France and Germany the 94 octane is used by a lot of people.

I do concede that the cost to do that here might be more expensive, but 87 octane is garbage and should be eliminated. Maybe I was a bit extreme in saying 91, 93, 95, but there is no reason we can't be 89, 91, 93. Then most people could buy the new "mid-grade" instead of premium (which nearly all European cars require as they are designed to run on "regular" European gas)

Dyn

As 2015+ manual states.

The 2014 clearly states this is a no no.

Multiple people keep stating this as a C7 fact. It is not.

m3incorp

I notice that on the military post here in GA, they keep running out of 93 and 91 over the past month of so. Costco a few miles away doesn't have this problem.

spinkick

87 is fine but with reduced power in the LT1, the Z06 LT4 its a no no. 89 is the lowest you should go in the Z. Says it right in the '17 manual.