I just bought a 2004 4Runner V8 with 270k miles. The last owner said he kept the engine running this long by only using 93 premium fuel. I get that regular oil changes are key, but does fuel type really matter that much? And what if I switch to regular fuel now, after years of him using 93?
Just use what the owner’s manual says. Higher octane fuel won’t really do anything if the engine’s not designed for it.
Mars said:
Just use what the owner’s manual says. Higher octane fuel won’t really do anything if the engine’s not designed for it.
Higher grade fuel is harder to burn, which is why it’s for high-compression engines. OP isn’t gaining anything except a bigger bill. It’s better to pick a good gas station to avoid bad fuel or water in the tank.
It won’t make much difference in a regular, non-turbo, low-compression engine.
More important than octane is getting gas with good detergents to keep the engine clean.
Will there be problems if I switch to regular fuel after years of 93?
Nope, no issues.
The guy you bought it from probably didn’t need to use premium. There’s no benefit to using higher octane if the manual recommends regular. For a Toyota, 87 is great and will keep it running forever.
Doesn’t matter. The 4th gen 4Runner says it needs 91, but it can adjust itself to run on 87.
You just don’t want to go too low and get engine pinging. 93 is overkill—87 should be fine.
In the US, the only difference in fuel grades is the octane level, which is just the fuel’s resistance to igniting from pressure alone. High octane is only necessary in high-compression engines. Using it in a regular engine is just a waste of money—it doesn’t improve mileage or engine life.
Look for ‘Top Tier’ fuel, which has better detergents to keep the engine cleaner. That’s what matters more than octane level.
Other parts like suspension and rust are more likely to wear out before the engine.
I would’ve sold my Sequoia if I had to put premium in it all the time. I’m still getting 15mpg at 275k miles.
My 05 V8 is at 316k miles, and I’ve been using regular gas for almost 150k miles with no issues.
I use mid-grade in my ‘07 Matrix because it feels smoother and lasts longer, but that could just be my gut feeling.
Just stick to name-brand (Top Tier) fuel. Regular unleaded is fine. Oil changes every 3k miles, even if the oil says it can go longer.
Wait, when did Toyota start putting V8s in 4Runners?
Stick with Top Tier fuel and the recommended octane level.
The previous owner wasted a lot on premium fuel for no reason. Octane level doesn’t affect engine life unless the engine specifically needs higher octane. Use what the manual says, probably 87. The engine won’t know or care that it used to get 93.
Toyotas run better on premium, and Japanese cars don’t like ethanol. I always use ethanol-free premium in my Toyotas to avoid pinging. I only put 87 in my old American cars.