Car & Driver: Is Premium Gas Worth It?

[LimitedSlip]

Interesting read:

https://www.caranddriver.com/reviews...dodge-charger/

[extrashaky]

The takeaway seems to be that it might be beneficial or it might not.

So this article basically tells us nothing at all.

[Leonardo]

All cars tested made more HP and were faster 0-to-100 with 93 octane vs 91 or 87octane . Not surprising to me...

[PetrolioBenzina]

Not worth it. E95 is where the fun is.

[Tokay444]

Article clearly written by layman.

[Mic7796]

Originally Posted by LimitedSlip

Interesting read:

https://www.caranddriver.com/reviews...dodge-charger/

So for these larger engines an average of 0.3 miles per 4 bucks of gas is NOT worth it money wise, what does it do for our Flat 4s, which would be more relevant ?


Sent from my iPhone using Tapatalk

[Slammillionaire]

An article about premium vs regular gas that makes no mention of compression ratios? WTF?

[extrashaky]

Originally Posted by Slammillionaire

An article about premium vs regular gas that makes no mention of compression ratios? WTF?

Yeah, that was one of my complaints about it. The CRV is obviously a low compression engine. You wouldn't expect to see any difference, and you don't.

The BMW is a high compression engine, so you would expect to see a difference, and you do. But where they characterize the difference as a benefit of using 93, it's actually a detriment of using 91.

It's hard to tell what's going on with the Ford and Dodge, but it's obvious that the increase with the Ford is specific to their engine management system and has no predictive value at all with regard to other vehicles. In other words, so what?

It's a clickbait throwaway article aimed at dimwits.

[Impureclient]

Not sure where all this is even going. Our cars are designed to run at 93. 91 can be used in a pinch. 87 is just not to be used. End of discussion.

If anything maybe a "this is how you increase 87 octane to 93" article would be more relevant. Anybody adding anything crazy like xylene to do this?
I know I can get it for $50-60 a 5 gallon bucket so at roughly $10-12 a gallon I wonder what that will take and at what cost to create 93 from 87?

Not that I am recommending to do so but I am sure somebody in here has experimented with adding some stuff to do this.
Using the Race brand race gas additive it looks like it would be about 30 ounces to raise a 10 gallons from 87 to 93, so almost two 16 oz. cans at $20 a pop($40 total).
Xylene seems the stuff people try the most or I've read Acetone and Toluene also have been used too.

[NoHaveMSG]

Originally Posted by Impureclient

Not sure where all this is even going. Our cars are designed to run at 93.
Xylene seems the stuff people try the most or I've read Acetone and Toluene also have been used too.

I don't even have access to regular 93. Most of the time it is 91. I have logged my car a lot. With 91 it is a bit knocky around 2500-3000 unless I am super gentle with it. Above 4k it is completely fine and IAM holds at 1, if it is really hot it will drop down into the .9's. If they put 87 in it by mistake the IAM drops to about .4 Car feels like a dog, even in neutral it revs really slow.


We used to use the Acetone trick on our dirtbikes when we couldn't get race fuel.

[extrashaky]

Originally Posted by Impureclient

Not sure where all this is even going. Our cars are designed to run at 93. 91 can be used in a pinch. 87 is just not to be used. End of discussion.

I don't know what OP was thinking by posting it, but I understand where the question for the article came from.

There are many people who waste money on premium gasoline in cars that don't need it. Since many high performance engines have high compression, and high compression engines require higher octane, these people get the causal relationship backwards and think that the higher octane causes the higher performance.

They apply this incorrect cause and effect to their own vehicles and conclude that using higher octane gasoline will give them better performance. Since they don't want to be wrong, they imagine they're right and perceive higher performance that isn't really there. That's confirmation bias. If you show them actual dyno runs that dispute their belief in magic, cognitive dissonance will kick in, and suddenly they'll be talking about "improved throttle response" or "smoother idle," which conveniently can't be measured except by feel. Or they'll claim better fuel economy, measured in nonsense like "miles per tank."

Usually these articles fall into one of two types. First is where somebody who has no idea what he's talking about tells people that they should run premium in their cars for the "better detergents" to keep the fuel system clean and clear out deposits. I always suspect these are oil company shills.

The other is where compression ratios are discussed, then the fuel is tested through actual dyno runs and fuel economy tracking. Those almost always conclude that premium is a waste of money in lower compression engines.

This article tries to be both and fails miserably. The results are inconclusive, and the writer has no idea why. I suspect some of it is just sloppy data gathering that can't be duplicated, but I'd be really interested in an explanation for the difference with that Ford because it runs counter to what you'd normally expect from a real scientific test.

But none of this has anything to do with us.

[Sasquachulator]

IT should be simple....

Whatever the car's minimum requirement is, you use that.
You can use higher than minimum if you want but you probably wont get much if anything out of it.
But don't go lower just to 'save a few bucks'.

[serialk11r]

Originally Posted by Impureclient

Not sure where all this is even going. Our cars are designed to run at 93. 91 can be used in a pinch. 87 is just not to be used. End of discussion.

If anything maybe a "this is how you increase 87 octane to 93" article would be more relevant. Anybody adding anything crazy like xylene to do this?
I know I can get it for $50-60 a 5 gallon bucket so at roughly $10-12 a gallon I wonder what that will take and at what cost to create 93 from 87?

Xylene seems the stuff people try the most or I've read Acetone and Toluene also have been used too.

That's too expensive, E85 is the only octane booster that's cost effective, because even in Cali it's barely more expensive than gasoline per LHV BTU. Anything else that's in liquid form is more money (I would imagine you could theoretically dissolve more propane into your gasoline, but it seems like a good way to kill yourself). You'd need something like 20% xylene to get to 93 from 87. I recall back when I had my FR-S I tried the 87 + E85 blend just to see and the car liked it, but I saved a whopping $1 on the whole tank compared to filling up with 91 or something silly like that.

Xylene and toluene would be great if you could get them at industrial prices, but there's no such thing as a xylene or toluene fuel pump, so the distribution cost goes through the roof. If you need better than E85 though they're probably the only choice.

Theoretically, you could run a turbo car or really fast high compression NA car on 87 if you air temps are cold and you're careful to never press the gas too hard. E.g. cruising from SF to LA with 87 or 89 in the tank instead of 91. Then as you go into the city where you need acceleration again, you could dump a jug of E85 in the tank and you'd be okay. Kind of not worth the 2 dollars though lol. I actually never saw any knock with my FR-S running 91 (the only choice in CA) while I was logging it, but I only ever logged it on cold days. With more aggressive timing I'm sure you could easily see the benefit of 93 everyday though.

[Tokay444]

Methyl hydrate (methanol) is a great octane booster.
In DI applications, it alone carries an effective octane of 180.