what gas for '95 accord vtec?
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Joined: Mar 2005
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From: NASHVILLE, TN
Octane is a term used in relation to a specific hydrocarbon chain. Oct=8. Octane resists combustion under compression better than its closest chemical cousin Heptane (which makes up alot of the remaining 13% of 87 octane gas). 87 Octane= 87% C8H18 (octane). Thus an octane rating translates loosely to how much compression fuel/air can take before it combusts. An engine with a high compression ratio needs higher Octane gas so that the gas will hold up to the compression until the spark hits. Diesel fuel has a Cetane rating. Cetane is highly combustable under compression.
If your engine has a compression ratio of 10:1 or less putting anything better than 87 is a waste of money.
The percentage of cleaning agents in pump fuel is very small. It has to be. if it were much higher than it is we would all be having our engine heads done every 100k miles whether we like it or not.
The detergents in gasoline are typically noncombustable matierials and if they are used too often or in too large a quantity they will glaze the exhaust valves, ports, and manifold (and prematurely foul a catalyst) leading to a number of other problems; not the least of which is bad engine performance.
Advancing and retarding the timing on any engine will effect the compression ratio to some degree but will only stop pinging in engines in which the compression ratio is borderline.
Plus (89 octane) is a joke. The Octane rating is an average and many times you will be paying $.10 more a gallon for 87.5 Octane gas. Two points is typically not enough to make much of a difference. Rarely will you see a vehicle that calls for 89.
If your engine has a compression ratio of 10:1 or less putting anything better than 87 is a waste of money.
The percentage of cleaning agents in pump fuel is very small. It has to be. if it were much higher than it is we would all be having our engine heads done every 100k miles whether we like it or not.
The detergents in gasoline are typically noncombustable matierials and if they are used too often or in too large a quantity they will glaze the exhaust valves, ports, and manifold (and prematurely foul a catalyst) leading to a number of other problems; not the least of which is bad engine performance.
Advancing and retarding the timing on any engine will effect the compression ratio to some degree but will only stop pinging in engines in which the compression ratio is borderline.
Plus (89 octane) is a joke. The Octane rating is an average and many times you will be paying $.10 more a gallon for 87.5 Octane gas. Two points is typically not enough to make much of a difference. Rarely will you see a vehicle that calls for 89.
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Joined: Jun 2003
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From: Orlando, Florida
So, what do you suggest we do for our engines that detonate severely with anything less than 93? I've completely tuned the engine, new fuel filter, ran fuel treatments, cleaned the EGR ports, etc. the ONLY thing left to do is retard my timing a little...even though the car is running perfect otherwise.
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From: New York
Originally Posted by jobrien
I didn't say that all gases did not have detergents. I said running a higher octane tank through once in a while would help clean. I said this because a higher octane fuel burns more efficiently thus more of the fuel is burned in the chamber and this CAN help keep it clean.
Using higher octanes CAN cause your car to run more efficient too because more of the gas is burned/ignited in the chamber so more of the fuel is being burned instead of going out your tail pipe, which means potentially better gas milage too.
Using higher octanes CAN cause your car to run more efficient too because more of the gas is burned/ignited in the chamber so more of the fuel is being burned instead of going out your tail pipe, which means potentially better gas milage too.
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Joined: Oct 2004
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From: Atlanta Area, GA
Originally Posted by benjamin
When the engine is fully warmed up, there shouldn't be any undetonated fuel exiting the tailpipe. If there is, something else is going wrong. I don't know where you got the idea that higher octane fuel burns more completely than lower octane fuel, but it isn't true.
I missed Sean
Joined: Aug 2004
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From: Fairfield/Bridgeport CT
Originally Posted by JL95AccorD
I had never heard that. I know that the timing can cause pinging if you use a lower octane. He says that he gets pinging with a lower octane, not that he pings in winter but then it goes away in spring. How does the climate affect it?
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From: New York
Originally Posted by jobrien
Then why are there race fuels and why does my race bike (and cars too) run better on the higher octane race fuels?
Think about it this way: a naturally aspirated Honda Accord only requires 87 octane fuel. If you put a turbocharger on that same engine, it will require higher octane fuel because you are increasing compression.
Generally speaking, an engine designed for high octane fuel is also designed to function with lower octane fuel, but it will produce less horsepower. An engine designed for lower octane fuel does not produce more horsepower with higher octane fuel.
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Joined: Dec 2003
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From: Texas
I used only premium stuff until I compared the performance to lower grades. Personally I have not seen any appreciable difference in power. With prices going up I only buy middle grade or lower now. Heck, years ago when I could get 104 octane I tried it in my V8 Ford with stock compression, but still felt no difference in power. Before ECUs (yeah I remember that), I think detonation was more of a problem. I've never had an ECU equipped car so much as ping once.