Octane grade

[shotokan]

which is more better / preferred of gasonline octane grades for Toyota 4K engines?

1. Octane 95, 93 or 91?

Gusto ko lang pong malaman ang pagkakaiba nila...

Salamat.

[youngrider]

Double post

[youngrider]

I think it doesnt matter much, (though i will prefer at least 91 octane) what must be remembered is that the old gasoline engines are prone to valve seat recession when using unleaded gas. The lead acts as a cushion to prevent this from happening.

The problem is, do the regular gas available now still contain lead or any lead substitute, or the term regular is used now to denote lower octane rating.

[redorange]

If your engine is designed to use leaded gas then you have to use some type of lead substitute for your engine when using unleaded fuel. The lead in the fuel acts as lubricating agent in the engine and without it seals may become damaged over time. The lead also prevented detonation in high compression engines, if your engine is high compression then you have to use the higher octane which is 95.

Octane is gasolines ability to resist detonation, the higher the number the more resistant to detonation the gas is which is good for high compression engines. If you use a low octane on an engine requiring a high octane you will have detonation and cause damage to you engine over time. If you have an engine not requiring a high octane and you use a high octane fuel you are just wasting money since it does not benefit you or your engine in anyway. As for the midgrade fuel 93 just ignore it since it really serves no purpose at all the gas companies placed it there for people who are unsure of what to use.

[red888]

i think the 4k is also suited for 91 octane...

[niky]

I'd prefer 95 octane for an engine of that age.

If the lack of lead is a concern, you can always have the valves replaced with hardened ones... generally a good idea given the engine's age, anyway.

[niky]

I'd prefer 95 octane for an engine of that age.

If the lack of lead is a concern, you can always have the valves replaced with hardened ones... generally a good idea given the engine's age, anyway.

[shotokan]

may nakapag sabi kasi sa akin,,, mas maganda raw gamitin yung 95 or higher octanes kasi daw kung ano yung mas mataas mas maganda...

others naman,,, ang sabi di daw maganda gamitin yung 95 kasi masyado daw mainit sa makina...

minsan kasi kinakargahan ko ng 93 lang at minsan din kinakargahan ko rin ng 95 sa ibat ibang gaso stations....

[daimaoh]

+1 ako dito.

your just wasting your money since most engines only need a minimum of 87 octane... unless your using a high performance engine.

the proper octane rating for your engine should be on your car manual. Or just research it on the internet.

pwede to use a higher octane rating for older engines (especially due to knocking & pinging) ... but then again, the engine might just need to be tuned. worse, overhauled.

If your engine is designed to use leaded gas then you have to use some type of lead substitute for your engine when using unleaded fuel. The lead in the fuel acts as lubricating agent in the engine and without it seals may become damaged over time. The lead also prevented detonation in high compression engines, if your engine is high compression then you have to use the higher octane which is 95.

Octane is gasolines ability to resist detonation, the higher the number the more resistant to detonation the gas is which is good for high compression engines. If you use a low octane on an engine requiring a high octane you will have detonation and cause damage to you engine over time. If you have an engine not requiring a high octane and you use a high octane fuel you are just wasting money since it does not benefit you or your engine in anyway. As for the midgrade fuel 93 just ignore it since it really serves no purpose at all the gas companies placed it there for people who are unsure of what to use.