I run Chevron 91 almost exclusively. I don't much care what our manuals say as my piece of mind is preserved by running higher grades of fuel. I stick with Chevron for consistency/quality.
My manual for a 15 is the same as Steve's, 86. The myth: Higher octane rating equals higher grade of gas. Most people who know more than me agree that is not true but is still appears to be a belief of many.
Honestly it may not matter on most newer fuel injected vehicles, however my personal experience has been better performance with higher octane ratings on my older vehicles. I'm more brand specific for the same reason as I've had issues with many of the off brand fuels. Mostly your paying for the additives at this point. If I remember correctly most fuels are mixed from the same base gas, only a few suppliers own the whole chain. Amaco was one of them. I've gotten the best/most consistent performance from Chevron and Conoco. Conoco's are few and far between on the West Cost so Chevron is my station of choice. The extra price is worth it to me for the piece of mind it brings. Just my .02...or .25 if I'm at the pump
Well, if you use 91, enjoy. I'll keep the $$ difference and use it to pay for more accessories until my bike looks like Pee Wee Herman's.
Former Ride:
2013 F6B Standard, black; sold 7/2019
Latest Addition:
2016 Gold Wing Level 3, red; SCT transmission stuck in manual mode
2019 Miles:
7,900 as of 10/6
Its not what you think.....this mornings price at my local store: $2.93 for 87 octane unleaded and $3.47 for 91 octane ethanol free premium. If you do the math and use a 6 gallon fill up, it will cost you $17.58 for regular and $20.82 for premium. If I get 41 mpg on unleaded, I'll get a 246 mile ride for my 6 gallons. For the same 6 gallons, I'll get 264 miles at 44 mpg for the premium. Break it down to the per mile fuel cost and it costs me $0.1399 per mile for unleaded and $0.1268 per mile for premium so.....Its cheaper for me to run the premium, get better mileage and what I perceive as better performance.
Yes that ethanol free fuel is better. Much more per gallon than mix in this part of the world but better. I run it in lawnmower, chain saw, generator and boat.