I know that forced induction vehicles (turbo/supercharger) need the premium, because of the higher octane. But , what are the advantages of putting premium in a naturally aspired engine, besides better gas mileage. What does it do for the engine. This may be a stupid question but i was just wondering.
Thanks
Many will argue that it does nothing.. Unless you have a high horse power engine with a 4 barrel.. If your running Fuel injection the ECU compensates so it doesn't really matter.. At least that is what most have told me. I have never done any testing however..
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the octane rating is a fuel's resistance to pre-combustion or detonation.... some people know it as knocking....... boost creates high pressures that make it easier to ignite the air fuel mix..... however if left unchecked it will ignite too early..... so a fuel with a higher octane rating is needed to resist early combustion..... the difference between 87 and 93 is so negligible on NA engines that it really doesnt matter what grade you get.... high octane fuel will only be noticeably different if you have boost or high compression
the octane rating is a fuel's resistance to pre-combustion or detonation.... some people know it as knocking....... boost creates high pressures that make it easier to ignite the air fuel mix..... however if left unchecked it will ignite too early..... so a fuel with a higher octane rating is needed to resist early combustion..... the difference between 87 and 93 is so negligible on NA engines that it really doesnt matter what grade you get.... high octane fuel will only be noticeably different if you have boost or high compression
Excellent explanation!
The same goes for leaded fuels. The lead content helps to control detonation allowing you to run higher boost levels. Just don't use it unless you are running catless. And no, it won't clog your injectors.
Due to outrageous gas prices, car manufacturers are trying to get better mileage, which i'm sure you know. With a higher octane fuel, they can lean out the mixure a bit more without fear of detonation, and get better mileage at the same time. I bet if you did the math as mileage per dollar instead of mileage per gallon, you still be spending more due to the 20 cents or so per gallon. That's a clever marketing trick if I ever heard one.
Also might add in that usually if the 87 doesn't cause any problems, then the 93 high octane very well may cause you to loose performance, and get worse gas mileage. The only reason to go to a higher octane rating, as stated above, is if spark knock is an issue. Then you want to go just high enough to rid of the spark knock. This is probably why some of the newer engines say 91+, I know that the Magnum 318's in Dodges are very prone to spark knock, so a lot of 318 drivers have to use higher octane. "Premium" for 93 octane must be another one of those marketing gimmicks to make you think you're getting better gas.
I know most luxury cars need premium gas... they tell you it's because they're precision tuned engines and all that. But premium gas does give you better performance anyway, so why not use it? I've been running 93 octane since the day I got my car (only got 91 a couple times.. since usually pumps only offer 87, 89, and 93 around here).
I know most luxury cars need premium gas... they tell you it's because they're precision tuned engines and all that. But premium gas does give you better performance anyway, so why not use it? I've been running 93 octane since the day I got my car (only got 91 a couple times.. since usually pumps only offer 87, 89, and 93 around here).
Because 90% of the time, you're just throwing money away, and most cars, it doesn't improve performance. There is LESS combustable fuel in the mix to prevent detonation. These luxury cars are probably tuned to run on the 93 octane, and if you run 87, guess, what, spark knock :-) Spark knock kills performance, and will kill an engine prematurely, so in that case, yes, it does give better performance (by reducing/eliminating knock). In some cases, like the SRT-4 I believe, the computer can detect the knock and reduce timing. I forget, but I think if you put like 100 octane (or whatever rating is up there), the SRT-4's actually do get performance gains because the system can add timing, etc. So, in cases like the SRT-4, the higher octane ratings can see peformance gains.
If the car doesn't call for it, and it's not spark knocking, don't spend the money on higher octane. If it is actually providing better performance, then either your butt-dyno is fooling you, or there is some inaudible spark knock you weren't aware of. ;-)
in a sence. if the man. reccomends 87. and you use 89, in a way your saving your self in the long run. higher octane burns that much cleaner. which will prevent you from, clogged inecjetors and jst gunk.
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