[1988flhtc in nfld]

so 80 ci carbed, with hypercharger ,thunderheader,andrews ev 27,should i be usingregular, or hioctane gas? any improvements with the hi octane, run cooler, or was the old engine designed to run on regular unleaded?

[duke76]

I always use premium whenever I can, keeps the fuel system cleaner and then if you ever get into some crappy gas the premium that is left in the tank should help to offset it, you could probably get away without using it if you havent raised your compression but if you figure out the cost difference and how many gallons a year you are using you arent saving a bunch of money plus the premium is less likely to varnish up in the wintertime because of the additives it has in it, Todd

[BluePearl]

Havn't you heard about the doomaflot sensor on those carburetors if you use low octane it tells your motor to run like crap!!

But seriously I'm with Todd the octane isn't biggest deal but the additives in the premium gas are alot better and when your talking $1 or so per fill up why not?

Now if if you want to talk octane - go 120 racing fuel will make your 80ci into a 103SE - for a little while anyways

[sarge7]

hi-octane 93 - only way to go. The extra additives are worth the cost, it won't make it run like a hopped up rice burner - but it will run better and last longer.

[voodoo1]

Every now and the n little of our racing gas gets in the tank with a mix of 93 oct. Used to sneak it into everything a little bit a time (octane booster) Minibikes,push mowers, riding lawn mower,go carts, dirt bikes,my own cars as a teen. My dad by race day would be wondering where all the racing gas went. Hey we even put in an ol' roto-tiller. Stuff has a distinct smell coming out the exhaust one can learn to appreciate. To this day a little bit every on now and then gets in the tank to "help out". the rest of the time 100% 93 or Shell or 93/94 Sunoco gas. You will notice a difference in how far you turn the throttle to get er going and keep it moving, It will be a little less than if you are used to using lower octane "stuff".

[Carl Blanchard]

It dosn't matter how old the engine is 1988, your engine will run a lot cooler on sup, and cleaner.Don't let anybody tell you that gas is gas.

[chucktx]

agree............

[Lucifer]

Altho the service manual for 85-90 Softails says a minimum of 87 octane, run the highest available octane, the difference would be less than a buck on a fill up.

[whacker]

I always put in the highest octane gas I can find in my 75 Sportty.

[voodoo1]

ya see em' out here spending a Wahzoo on the bike then put in low gas?!?!? to save?

Later
Voo1

[Lucifer]

Originally Posted by voodoo1

ya see em' out here spending a Wahzoo on the bike then put in low gas?!?!? to save?

Later
Voo1

Sooo true...try to save $.75 per fill up and after 100 fill ups got enuf for another chrome doodad

[shovhd]

I'm not going to argue that the additives in premium gas aren't better for your engine than those in mid-grade or regular, but while doing some research on how best to fuel my beast (11-1 compression pistons) I ran into these posts. Lots of good info that dispels many myths about premium gas. ie: higher octane = more power. I guess the bottom line is...if your strictly interested in engine performance run the lowest octane gas, purchased from a quality distributor, that you can without your engine knocking, pinging or experiencing pre-ignition. I personally believe the additives in a mid-grade fuel are sufficient to ensure a clean running engine, of course I have to run Chevron 94 at sea level with a couple of heat range colder spark plugs.

Regular or Premium? - Feature/Features/Classic Cars/High Performance/Hot Lists/Reviews/Car and Driver - Car And Driver

Ruminations on the Effects of Octane on Motorcycle Engines

All About Detonation

Gasoline FAQ - Part 3 of 4