Premium Gasoline
- Thread starter Escape08
- Start date
Higher compression gives better gas mileage and more power.
If it has a turbo, it needs premium. Some companies say you can use regular in them, but it's not a good idea 
I fixed that for you.If it has a turbo, it needs premium for maximum performance. Some companies say you can use regular in them, but it's not a good idea
Thanks for the replies, so this is a win-win situation that we're saving fuel. I don't question my Jaguar 2.0 because it gets 33 mpg, but my wife's Volvo XC90 gets 26 mpg both uses premium, thinking of trading the Volvo in for a used Lexus RX 350
My Mazda CX5 has the 2.5L turbocharged engine. It is also a high compression engine. Mazda's engineers designed the car so that you can run as low as 87 MPG octane without pinging, but you don't get the full 250 horsepower unless you run 93 octane. You give up about 25 HP with the lower octane. And many owners report they get better mileage by a couple of MPG with premium fuel too.
I suppose if I was going to make a long freeway road trip I might use lower octane to save a few bucks but I live in the mountains and want all the power I can get so I use nothing but premium.
My Jaguar has a supercharged V8 and god forbid using anything less than 91 octane. I'd use 93 if it was available in California,
I suppose if I was going to make a long freeway road trip I might use lower octane to save a few bucks but I live in the mountains and want all the power I can get so I use nothing but premium.
My Jaguar has a supercharged V8 and god forbid using anything less than 91 octane. I'd use 93 if it was available in California,
I've always wondered how two engines with similar compression ratio and boost can need different AKI gas.
eg: EJ25+Turbo vs 2.0L Ecoboost
eg: EJ25+Turbo vs 2.0L Ecoboost
Direct injection vs. port injection.
Depending on the engine.
My VW 1.4tsi dint need premium. It has same performance and fuel; mileage with regular. In fact it had snappier throttle response with regular. I guess it's Direct Injection magic. I am one to give the engine higher octane if it wants it.
I bet engines tuned for max performance rather than economy would benefit from - and require premium.
I know the Four Cam V8 in my 1993 Lincoln Mark VIII would knock like crazy if the octane was too low. They tuned it for max performance and no timing pull back or EGR coverup - which can make an engine bog badly. Strong engine! Too bad OBDII and tuning changes killed that motor.
If the aim is to save money vs. get maximum power, consider whether the extra MPG offsets the extra cost. The spread between fuel grades is getting pretty wide these days.
The vehicle MFG wants the vehicle owner to experience the most out of that engine. Whether or not the owner can actually feel any differences is dependent on how the vehicle is driven. Years ago, higher octane may have been more of a necessity than is actually is today.
All modern engines have knock sensors. A knock sensor is a piezo-electric (PE) device that produces an electrical signal when the device is vibrated at a specific frequency range. The engine computer dials back ignition and cam timing when it receives signals from the PE sensors. I understand the desire to use less expensive gas, but I bought my car because of its performance.
What most don't understand, is that ALL manufacturers perform testing on premium fuel... even Lexus
This is what their performance numbers are based on.
The funny thing with Lexus, is that the previous generations of RX were specced for premium and as a result they performed flawlessly.
The newer versions aren't....so what changed machanically? Nothing!
Lexus realized that most people cross-shopping an RX with anything else will balk at running premium...but regular- now we're SAVING money
Sure, the Lexus will run on regular, but it may run slightly rougher, consume a little MORE fuel, and take a little longer to start.
This is the difference between "recommended" and "required" octane ratings
But hey, we're saving money!
This is what their performance numbers are based on.
The funny thing with Lexus, is that the previous generations of RX were specced for premium and as a result they performed flawlessly.
The newer versions aren't....so what changed machanically? Nothing!
Lexus realized that most people cross-shopping an RX with anything else will balk at running premium...but regular- now we're SAVING money
Sure, the Lexus will run on regular, but it may run slightly rougher, consume a little MORE fuel, and take a little longer to start.
This is the difference between "recommended" and "required" octane ratings
But hey, we're saving money!
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I suspect the majority of Lexus vehicles are driven in such a way where the owner wouldn't experience a difference between 87 and 93.What most don't understand, is that ALL manufacturers perform testing on premium fuel... even Lexus
This is what their performance numbers are based on.
The funny thing with Lexus, is that the previous generations of RX were specced for premium and as a result they performed flawlessly.
The newer versions aren't....so what changed machanically? Nothing!
Lexus realized that most people cross-shopping an RX with anything else will balk at running premium...but regular- now we're SAVING money
Sure, the Lexus will run on regular, but it may run slightly rougher, consume a little MORE fuel, and take a little longer to start.
This is the difference between "recommended" and "required" octane ratings
But hey, we're saving money!
I am concerned about LSPI, so I run the best fuel I can find, non-ethanol, premium, 91 octane in my BMW turbo (B46tu engine).
The owner's manual "recommends" 91 octane to get advertised HP and fuel economy. The minimum "recommended" fuel is 89 octane. They state that 89 octane "may produce knocking sounds". Premium may cost a little more, but the car sips fuel, (avg 30 mpg) so I don't really care.
The owner's manual "recommends" 91 octane to get advertised HP and fuel economy. The minimum "recommended" fuel is 89 octane. They state that 89 octane "may produce knocking sounds". Premium may cost a little more, but the car sips fuel, (avg 30 mpg) so I don't really care.
I've never seen a paper or study showing a connection between LSPI events and fuel octane rating. Have you? LSPI and regular pre-ignition knocking are not the same thing and have different causes.
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Feel like I'm repeating myself but the then new 2015 GTI. fuel door said premium required. VW realized that was a marketing mistake, some people won't buy the car as a result. 2016 the door said premium recommended, regular can be used 87, then in the brochure an asterisk where the HP/TQ numbers are achieved with premium.
Premium is 91, but where I live it's 93, 92, or 91. In Calif., 91.
Unfortunately 2/3 of our cars have premium recommended, and I use 93. It's being a 2nd class citizen with price gouging even at Costco.
My 1998 Maxima said premium recommended. I drove 20 years with regular, except when the knock sensor was defective. Got it fixed and back to 87. It went well over 300k, I just didn't get the 190/205 published HP/TQ on regular.
imho there is no relationship between mpgs and octane, octane does not measure goodness in the fuel blah blah blah. It relates to predetonation.
Premium is 91, but where I live it's 93, 92, or 91. In Calif., 91.
Unfortunately 2/3 of our cars have premium recommended, and I use 93. It's being a 2nd class citizen with price gouging even at Costco.
My 1998 Maxima said premium recommended. I drove 20 years with regular, except when the knock sensor was defective. Got it fixed and back to 87. It went well over 300k, I just didn't get the 190/205 published HP/TQ on regular.
imho there is no relationship between mpgs and octane, octane does not measure goodness in the fuel blah blah blah. It relates to predetonation.
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