If your owners manual calls for 91 Octane it's typically because the engine has high enough compression to warrant it.If your owners manual says to only use super, it is simply part of the marketing myth they are selling you about your car needing to sip Chivas Regal. Nonsense. All the money you save you could take your wife out to dinner once a week...
Put 87 octane into something like a Hellcat or a Ferrari and you’re in for a very bad time. They wouldn’t spec premium only if it wasn’t necessary.Interesting that when the EPA does all their testing of new automobiles they only use 87 octane gas. Guess that might be because all new cars are designed to run on 87 octane gas. Why burn midgrade or super in a car designed to run on regular? If your owners manual says to only use super, it is simply part of the marketing myth they are selling you about your car needing to sip Chivas Regal. Nonsense. All the money you save you could take your wife out to dinner once a week...
If your owners manual calls for 91 Octane it's typically because the engine has high enough compression to warrant it.
Interesting that when the EPA does all their testing of new automobiles they only use 87 octane gas. Guess that might be because all new cars are designed to run on 87 octane gas. Why burn midgrade or super in a car designed to run on regular? If your owners manual says to only use super, it is simply part of the marketing myth they are selling you about your car needing to sip Chivas Regal. Nonsense. All the money you save you could take your wife out to dinner once a week...
Depends. It's really a combination of compression, timing, and pressure. Forced induction engines may actually have a lower compression ratio but that's more than made up for with boost.
I'm thinking of the last few naturally aspirated performance engines I've owned, including my 6.4L which has a 10.9:1 compression and calls for 91. My wife's 5.7L "recommends" 89 and is 10.5:1 in comparison. My S62 also called for 91 and was 11:1.
I've noticed higher compression ratios over the years, even with a turbo. Not quite how they handle it other than with a lot of electronic engine management. My 1995 Integra GS-R had a "high" compression ratio of 10.0:1 and they recommended premium. There's a lot that can be done with a knock sensor and electronic ignition. However, my GS-R still used a distributor with a rotor and points. I never did it myself, but I heard that the timing could be adjusted by rotating the distributor. I think there was some sort of vacuum that could retard timing depending on the knock sensor.
Back in my Fox Mustang days you could bump the timing a solid 4 or 5 degrees if you ran 91, which added a bit of throttle response and made more power. That was a 9:1 engine (4" bore) and of course had no knock sensor.
Naw, they were pretty durable. Now, do that with boost, and yes, there was a risk of blowing something up. If you ran 87 with the timing advanced it would typically just rattle (ping) which definitely wasn't good, but I don't recall anyone ever having a failure from it.Couldn't you also destroy the engine in short order if you weren't careful? I thought one of the old tricks was that E10 was usually made with whatever octane non-ethanol fuel, but then the ethanol bumped it about 2 octane numbers. I think they called it "octane giveaway". But these days none of that is happening.
Interesting that when the EPA does all their testing of new automobiles they only use 87 octane gas. Guess that might be because all new cars are designed to run on 87 octane gas. Why burn midgrade or super in a car designed to run on regular? If your owners manual says to only use super, it is simply part of the marketing myth they are selling you about your car needing to sip Chivas Regal. Nonsense. All the money you save you could take your wife out to dinner once a week...
We run gas from our local Kroger 95% of the time...never had an issue or below par fuel mileage using it. The Kroger stores around here all get Trafigura...a non TT, unmarketed gasoline that meets the federal requirements.