87 Octane
- Thread starter Filthy
- Start date
FallenPhoenix
New Member
Filthy said:
you'll most likely lose a little power using high octane, the octane rating is only the fuel's resistance to ignition, which keeps it from detonating early. The only way you'd gain more power from higher octane gas is if the new 4.6 uses a knock sensor and adjusts timing accordingly.
holler said:
Well, I based my question on several different factors. One is that I currently own an Audi A4 turbo and it specifically states that the minimum octane is 91, putting in a lower octane voids the warranty. Also, if octane is not an issue then why do people buy octane boosters? Again, I am not an expert on engines and gas, but there must certanly be a viable difference between 87 and 93 octane.
golf4283
Active Member
The recommended octane is what you should use. There is absolutely n o benefit from a higher octane unless you are running a supercharger or something like that where you would need the higher rating. Ford did Americans a great thing and saves us a little money every time we fill up by using 87octane.
Svtpilot
Founding Member
Filthy said:
Octane Rating is the measure of the fuels resistance to detonation. Detonation is when the fuel/air mixture ignites from engine compression prior to the sparkplug firing. The result is "pinging" which can damage the pistons. So 91 octane gas has a higher resistance to detonation then 87 octane fuel.
Since compression of the mixture alone can cause it to ignite without a spark (which is how diesel engines fire with no sparkplugs) the higher the compression of a engine the more likely it is that detonation will occur. Advancing the the timing will also increase the likely hood of detonation. Since high performance engines normaly have higher compression an/or more advanced timing then normal engines they require higher octane fuel then normal cars. However engine managment technology is so advanced that it is possible to build a high preformance engine that runs on 87 octance like the new Mustang. Your engine like the one in my Cobra is desiigned to run on 91 Octane and use of lower octane will damage the engine.
As far as Octane boost back in the late 70s to mid 80s when the highest Octane you could get at the pump was 89 some cars needed Octane boost. Today I could be wrong but I would bet that 90% of people who use it are wasting their money. Some 60s muscle cars have really high compression engines that can't run on todays pump gas so if you owned one you would have to add octane boost. Beyond that, building a really high compession engine for your car or bumping your timing up to the max, I don't see the need for Octane Boost.
FallenPhoenix
New Member
Filthy said:
Octane rating, is the resistance to burning of a particular fuel. The higher the compression in an engine, the more likely the fuel is to get hot enough to combust before the spark plug ignites. So in high compression engines, higher octane is needed to prevent detonation or knock, which can destroy pistons and valves. If you were to put 114 octane race gas in your sister's camry, it would most likely run very bad if it would run at all, because it takes a bigger spark to ignite the high octane fuel.
The reason people say not to buy higher octane than you need is because the component that is octane, takes up volume that could be the fuel itself. Basically your replacing fuel with octane, the higher the rating is. Plus you're losing money because it costs more at the pumps. Octane boosters are bought and sold because people think it will help them get better gas mileage or more power, when in reality it does absolutely nothing for a normal engine.
Similar threads
