For those of you who just like to ride your Spyder...
Please skip this post. I won't blame you a bit. You're probably the SMART ONES!
For those that just enjoy forging ahead no matter the cost....Read On!
Without accurate measurement -- I refuse to believe you are getting better mileage with premium versus regular -- unless you happen to be using a fuel dealer that gets regular from the dregs . . . .
I went from East Tennessee to California and back, 5,500 miles checking each grade for several tanks. I rode about a 1,000 miles before changing to another fuel grade. I feel this is a pretty good baseline approach.
Each grade gave pretty consistant mileage numbers, though I did get the occasional stray bullet.
If I'm getting "Dregs" then every fuel dealer from here to California is selling dregs. I just don't think that was the case.
(I have witnessess, but really... I rode with a pretty nefarious bunch!
Breaking into a $4,500 BushTech trailer with a claw hammer! Where are the cops when you need them! The desk clerk at the hotel asked if we needed any help! :dontknow: So much for security! :gaah
Anyway, getting back on track here...
The ONLY thing that premium prevents is knocking.
You are technically correct. However, that is not the whole story. If Premium fuel is preventing 'Knock', it may also prevent the ECU from retarding ignition spark timing? Spark timing is critical to performance and fuel mileage.
You have to ask yourself how a compression ratio that would normally require 100 Octane works 'Fine' with 87 octane?
On the Spyder, when the ECU senses 'Knock', ignition timing is retarded until the knock condition goes away. This reduces power and performance but allows a low compression fuel to be used in a high compression engine.
This ignition timing retardation isn't something that will smack you in the face or add 2 seconds to your 1/4 mile time. But it will show up in fuel mileage.
The hotter the engine gets, the more the ECU has to retard timing to keep 87 octane from knocking. So on hot days or in city traffic, the potential for premium fuel to boost relative fuel mileage is increased.
It does not clean your engine nor fuel system. .
You are absolutely right here, but this is not the reason I run Premium fuel.
It CANNOT give better mileage.
Well, of course it can if the conditions I have referenced exist.
You can search the web to your hearts content and every reliable source will confirm this..
This is only true if you are talking about an engine with low enough compression so it can run regular fuel without performance compromising measures like anti-knock ignition timing adjustments. Or, if the timing is permanently retarded to accomondate low octane fuels and the system is not designed to take advantage of a higher octane.
This is not true of a high compression engine that retards ignition timing to accomodate low octane but can also advance ignition timing to take advantage of higher octane.
Any reports otherwise are only anecdotal and not factual.
All I can say here is that "Any" is a very big word.
My information may be all wrong and no one is obligated to believe any of it. Each one is welcome to give it a try for themselves, if they like. If no one else has the same experience it still does not necessarily invalidate mine.
The only accurate way to check mileage is to average 3 or 4 tanks by dividing miles by the gallons used. I use a spreadsheet that computes a rolling 3-tank average to ensure that I am not mislead by one or two tanks.
Not necessarily. On the California trip we stopped between 120 miles and 160 miles. I ran at least 8 tanks before switching fuel grades. I always top off to the bottom edge of the fill neck ring. This gives me a very consistant gallons added measurment.
I discounted the 1st tank on a new fuel grade because of dilution.
Why can't I just average these by adding them up and dividing by the number of tanks?
Granted, of the 2 methods yours will be more accurate. Still, I'd say we are talking a few tenths and not a big deal for my purposes.
If you can present such data, your reports will gain credibility -- but, will remain suspect because those results will defy science.
I agree that my data is anecdotal. It is what it is. I shared it because I'm not sure that most Spyder riders get the kind of chance I did to test different fuels.
If you expand your science to incorporate all existing parameters you'll see that it is possible to increase mileage with Premium fuel in at least some cases.
The real debate is not whether Premium fuel can improve performance and fuel mileage in some cases, as it clearly can.
The real question is, will Premium fuel increase performance and fuel mileage in the Spyder. We don't have enough information about the Spyder's hardware/software to say for sure.
That leaves us with reasoned speculation and anecdotal information, which is all I'm offering here.
I know people are skeptical, and I don't mind that. I reserve the right to be skeptical too.
I am not finished with my experiment. The next long ride I take I'll do the same octane testing again and see what I come up with.
Until then, I'm convinced enough to put my money where my statistics are. Premium in the tank for me.
