Rapid summary: RON is a measure of 'explosiveness' and / or octane. Contrary to VERY popular belief, high octane fuel is LESS explosive than low octane fuel. What this does is allow the fuel to be more compressed without spontaneous ignition, meaning when it's deliberately ignited by the spark plug (At JUST the right moment) the energy created is much more.

 

Essentially, high performance cars have high compression engines. Most cars, well, don't.

 

Running high octane fuel in a normal car will make zero difference, whatsoever*. Running normal fuel in a high compression engine will do one of the following:

 

-Cause pre detonation, where the fuel explodes prior to the spark plug lighting. This is pretty bad for the engine and obviously kills performance

 

-The ECU will detect the above and back the timing off. Engine will be fine but performance suffers heavily

 

*Regardless of what someone will no doubt say, any differences in performance are either because the car is specced for high octane fuel OR the high octane fuel happens to have better detergents in it which clean the engine.

 

Conclusion: Unless your car really is high performance / high compression, don't waste your money.

Haha, you wikipediad AND beat me to the punch. Ah well, my explanation was off the top of my head because I know this shit!

But that's an idiotic measure of "quality", isn't it?

So to sum things up I shouldn't put high RON petrol in my diesel car (giggle)

Well, I wasn't addressing you personally, but no, I wouldn't.

Since you know about these things. Should there be a noticeable difference in using higher RON fuel in a pretty standard 50cc moped?

If the weather would ever get nice I'd get my girl out and not cry so much about gas prices!

:-(( :-(( :-((

There is knowledge that you know, and there is knowledge that you know where to look to find.

Now I /know/ that's a bad idea.

Hey, wait a minute! I drive a Land Rover(at least part time)! It is a 1989 and I wouldn't say that it is a paragon of British fuel economy...

 

Wish we had Tdi 5s here.

Uh... it's twenty years old?

No car from 1989 is going to be great on fuel economy, whatever country it was made in.

Especially not a Land Rover - which was designed to rove land, not to save fuel!

They should use that in their advertising. "Got land to rove? Buy a landrover!".

Not that I've ever heard of. You'd hear it if it needed it for some reason.

Fair enough. Using higher RON fuel always resulted in an extra 5 mph on the top speed!

Donald Rumsfeld?

I was going to use it as my signature. I laughed my ass off when Peter posted that!

I don't know about no car. I had a car from 1987, namely a Ford Escort, that was incredible good on fuel. 40MPG on a trip was not uncommon and at least 30 MPG local driving was the norm.

A large SUV is of course quite lousy on fuel, but fully loaded with family, luggage and a rack with 4 bikes is an impossible task for the Escort. Plus if there is a creek to be crossed, the Escort would have to float it.

And?

you get shit mpg, I get 38+ round town in my landrover