Best fuel for the Viffer??

Thanks Steve, members like you are a real benefit to all of us.

Those with real life experience help us all. Thanks and stay on this board!

 

I usually run premium unleaded in my 2000. I find I get 20-30km better tank range than if I use regular unleaded.

 

It's my understanding that these two things are true;

High octane can ignite at lower tempuratures, therefore if your engine is running hot it can pre-ignite. That's when the heat of the cylinders lights the gas up before the sparkplugs fire. (I had this issue with my Hardley)

Higher octane is easier to burn, so when you spark high octane you get a bigger, faster, explosion. So more bang per liter. I think having higher potential energy has something to do with that too.

Is this the case Steve?

 

Canib,

Just the opposite is true in fact. High octane does not ignite as easily as lower octane fuel. It is designed to run in engines that have high compression or forced induction (turbo chargers or super chargers) which can pre-ignite lower octane fuels.

The energy content of all gasolines, regardless of octane rating, is the same. The ONLY thing different octane fuels do is change how easy it is to ignite the fuel/air charge.

Many modern cars are equiped with knock sensors that retard the timing, which lowers the power output, when knock (the same as pre-ignition) is sensed. This has nothing to do with the energy content of the fuel but can lead to more power in a high compression engine when run on high-octane fuel that was previously running low-octane fuel and having its timing retarded.

http://www.shell.com/home/Framework...ss_releases/2004/gas_pump_guide_01072004.html
http://www.cartalk.com/content/columns/Archive/1995/July/01.html
http://auto.howstuffworks.com/question90.htm


-Mark

 

Here is another good link on octane, check it out.
http://www.angelfire.com/ia2/vmax/fuelnotes.htm

 

I've got a 2000 model and run 87 octane, from colorado to Iowa yesterday I averaged almost 50 mpg at 85 mph.