Any benefits to high octane

[tbolt2000]

Are there any benefit to running octane gas when towing? I had heard when towing use high octane gas.

[Lynnmor]

Winged One wrote:

tbolt2000 wrote:
Are there any benefit to running octane gas when towing? I had heard when towing use high octane gas.

Those days are gone.

I had a 70 Plymouth (liked high octane) that I decided to try a little mid grade in, just to see. Dear lord, you would think I put a bucket of screws down the carb's throat, for the fit it was throwing. Racing gas raised the octane enough not to kill the car.

You will know if you are running too little octane.

No, you probably won't know if the octane is too low. Horsepower, fuel mileage and engine life will suffer but you won't know without careful checking.

[Winged_One]

tbolt2000 wrote:
Are there any benefit to running octane gas when towing? I had heard when towing use high octane gas.

Those days are gone.

I had a 70 Plymouth (liked high octane) that I decided to try a little mid grade in, just to see. Dear lord, you would think I put a bucket of screws down the carb's throat, for the fit it was throwing. Racing gas raised the octane enough not to kill the car.

You will know if you are running too little octane.

[fla-gypsy]

Not unless the maker requires it in which case you bought the wrong truck IMO.

[Lynnmor]

drsteve wrote:
No. Computer controlled engines adjust their spark timing to eliminate preignition under heavy load.

That's true, but it can't adjust the compression ratio. Knocking can be caused by other factors besides spark timing. Ford recommends premium fuel for the little Eco-Boost engine due to the very high cylinder pressures.

[Mark_Kovalsky]

You don't need higher octane in high altitude. The mean effective pressure in the cylinder is lower due to the lower density air, so you actually can use lower octane fuel. That's why the octane ratings at the gas stations at high altitude are lower than at sea level.

[icanon]

I use what the manufacture suggests. Only time I use a higher octane is when I know I'm driving in high altitude.

[drsteve]

No. Computer controlled engines adjust their spark timing to eliminate preignition under heavy load.

[camp-n-family]

My manual "suggests" higher octane when towing. I've tried both and haven't found the extra expense was worth it. No real noticeable difference in power or mpg.

[2oldman]

no

[Sam_Spade]

downtheroad wrote:
Use what the manufacturer calls for in the manual.

This. If you are on the ragged edge of needing higher octane gas your engine will TELL you so with a pinging or knocking sound under load. There is NO other reason to pay for octane that you don't need.

[downtheroad]

Use what the manufacturer calls for in the manual.