I have been using 87 in my 88" S&S for years and also still when I did the 95" upgrade. I did not know that I was supposed to be using more. I put 8K on a VictoryI had for the last year, same thing 87. Sometimes 89 . No problems or difference in performance. Is it really nessecary to use anything more. My wrench says no and he doesnt buy the good stuff either. Just curious what others think and are using and can i get a real reason not to do this?

 

If she's not pinging, you don't need higher.

 

VERY interesting thread. Like some have said.......Does the 93 really get used or is it stale? I think I'll try regular next time at $10/gallon. ****!

 

This has been beat to death in many threads before....Use what is recommended, for performance and durability of engine...I hope saving 20 cents a gallon isn't the issue...If so a scooter would be better for those concerned!

milo8155
07 FLHX
03 FXST
Collierville,TN

 

If you have a high comp motor and it's hot out, you are likely going to need the high test fuel, if you buy fuel from a little small town outta the way type of place, I'd by the regular as likely the high test is old and stale fuel. I run the high test most of the time on mine, but I have 10.5:1 motor. but i do not get any pings if I run the regular fuel. For the extra $1.50 it cost's to fill with gold I really don't mind the saftey factor.

 

There are as many opinions on this as there are about oil. I use whats recomended for my engine. The difference really isn't much. .02

 

Engine designs are optimized for a given octane rating. Just because there's no pinging doesn't mean there's no damage. You've spent a lot of money on the engine upgrades to maximize performance. I can't understand why you would short-change all that work and money by using low-grade fuel. That's like building a state of the art computer then loading it with Windows 98. Yeah, it will work, but it's not optimal.

 

I had been using mid grade fuel in the RK. On the basis of what folks herehad to say, Itried myfirst tank of premium (91 Sunoco), and I could just about feel a small difference in performance. I'm now on my second tank of premium, tho no Sunoco was around when I needed it. Either way, it wasn't pinging on the mid grade, and premium has made zero difference so far in the fuel economy. Not sure what I'll do next tank.

 

My stock bike pinged even on 91/92 premium. Since reprogramming with SERT there has been no pinging. I still buy premium and make an effort to buy it from the stations that carry non-oxy fuel (pure gasoline without any ethanol) in their premium grade. If I downgraded to super or regular I'd have to buy gas with ethanol in it. It's supposed to be OK in our bikes, but I'd still rather not use it.

 

its all about the ping. there is no preformace gain with high test UNLESS u advance timing. u can retard timing to lose the ping on 87 but then u lose preformance.