Fuel grade question

Here's something I'm interested in getting others opinion on.

I usually put supreme gasoline in my bike. Why? Cause I was told to do so by the PO.

I was filling up one day and my boyfriend says "You don't have to put that high of octane in your bike. It's old. When it was new the 'good stuff' was just plain old 87 octane. I bet it will run better on 87."

Then he went into a schpeel about how gas is so much ethanol now that it's a wonder anything older runs on it and it's ruining the older engines. And if I could, to try to find a place that has gasoline not ethanol. (I have yet to find a place)

So this time I put 87 in it. I haven't run enough to notice any kind of difference.

What's everyone else run in their bike?

 

I run Mid grade. 90-93 octane. I jsut feel better about doing it. I'm not sure why... I wonder what the best octane rating would be.
I have noticed however, that no matter what gas I put in, a small amount of Seafoam make my mpg and my throttle response better. Of course I have to change my in-line filter out every other month.
I think the bikes like the sea-foam cause of the moisture reducer. Ethanol increases moisture in our fuel, and sea-foam politely removes it while lubing our engines.
Hmmm
-SLkid

 

I just run the regular...well, regular unleaded, of course; the bike seems jetted for it just fine, and I haven't had any problems over the past few years.

 

I run the 87 - no problems at all...

 

There's no need for premium gas in our bikes, unless you've done something to change compression or timing, or there's something else wrong with the bike.. e.g. running too hot.

Higher octane does not mean more power. It means that it's more resistant to detonation (spark knock). High octane gas actually has less energy than low octane.

Nitromethane is a whole another story, though....

 

Want alcohol free gas? Swing by a marina. But they'll hate you for buying 3 gallons.
Oddly, alcohol is used to REMOVE water from fuel systems, but it also attracts the humidity right out of the air. So, as long as you're buying fresh gas and running the bike, no problem.

I buy 87 octane and I very rarely have heard a little detonation while going up a long hill near my house.

 

I run the 87 octane. Bike runs like a champ and my mileage is around 52-55 mpg.

 

I run 110oct racing fuel about every 3rd tank it has lead in it to lube the top end and helps in not burning exhaust valves. The rest of the time I run 92 or 93 with a couple ounces of lead substitute. It seems to work well for me. And race gas smells kick a## when you pull into the bar burning race gas itll turn some heads It also burns slower so at night after a good red line stop light to stop light you can throw some really nice flames out your pipes :lol: ride or die

 

Doesn't it say under the side panel to use 91?

I run premium all the time.

And lowlife - I thought these were meant to run unleaded... why add it?

 

My 550RJ actually specifies Regular, which they still sold up 'til '86...

 

Shoot flames!? Really?? That sounds wicked. Where do you get Racing Fuel? Sounds like a good way to keep your engine clean. Thats why I use seafoam

 

I run premium in my 550s as atonement for the thrashing they receive...

 

bikes i tend to wanna run higher octane just cause it burns cleaner. cars unless its a high compression motor theres no need. usually revin high on a bike so on some bikes it runs better on the expensive stuff...

 

That is the "Research Octane Number" (RON)which is apparently used everywhere in the world except North America.

There is also the "Motor Octane Number" (MON) which as I understand it is favored by the aviation folks.

If you look your friendly neighborhood gasoline pump you'll see that the rating is (R+M)/2 which is the average of the RON and MON.

Rule of thumb is you add 5 to the North American octane number to get approximate RON. 87+5=92, just fine for your XJ engine.

 

It does? The stickers on my side cover were all painted over. I can see them I can't read 'em lol

 

Thanks Micarl, now it makes sense.

650boy, As far as octane running cleaner- not true.

SLKid - flames = not good. May look cool, but on a regular combustion motor like ours, either your exhaust valves aren't sealing right OR your combustion is so rich that there is excess fuel in the exhaust, unburnt, and when it hits the hot parts in the exhaust it is detonating. Bad. They do however make theses things that pump propane over your exhaust tip and keep a pilot lit... and as you give the motor gas, it releases more propane, more flame. Looks cool. Expensive and dangerous though!

Quick snippets...

http://en.wikipedia.org/wiki/Octane_rating

 

you could always add NOS. It's an octane booster that cleans out your engine and tastes great...just be sure to add two bottles per tank because 2 is better than 1! - words (paraphrase) of wisdom from sti2gsxr

 

:lol:

Should I get that off the cardboard display in the front of the store, or is the cold stuff out of the cooler better?

 

We've still got a few gas stations that advertise ethanol-free gas. I make it a point to fill up all of my vehicles at those stations. Lately I've been putting super into it to help make up for the crap that the seafoam worked loose over the winter. So far so good.

mikeg

 

Anyone have any good reads/links on effects of Ethanol? Anybody got posts on here specific to ethanols effect on XJ's?

 

Check this out
http://www.businessweek.com/lifestyle/c ... 058678.htm

 

Think about this. . .
Super has a higher resistance to self ignite; it's less flammable.
Regular cheap-o gas has the same energy, but ignites more readily, such as on a hot spot.
Diesel won't burn if you throw a lit match in it, but burns well under pressure. And has more energy per volume.

So, if you blended 5% diesel into cheap-o gas, do you get a fuel that ends up with a higher flash point ( higher octane) AND more energy? The trace oil would also help seal and lube the rings and valves?

(kids, don't try this at home. . . )

 

If only I had a working gas tank to test that on the non-road worth seca...

Anyone with a doner tank? I'll totally blend some diesel in... O_O

 

I was running high octane and on occasion having trouble starting the bike. I read somewhere that the higher octane stuff is harder to ignite, hence may cause starting trouble. So I have switched to the lower octane/ cheaper stuff and since then I have not had a problem starting the bike.

 

Two months ago everyone here was saying GO PREMIUM its better blah blah blah... then I do a little research into octane etc, realize now that it was all B-S. lol...errrrrr

I'm gonna go top off with some good old ghetto-gas and see how it runs

 

dpawl31, the lead substitute is for lubrication since are bikes don't have catilatic converters or O2 sensors there's nothing to harm by adding it(at least I didn't think so)

As far as the flames go its not like I'm shooting 3 foot fire balls out the exhaust its just a little flash of unburt fuel right after letting off after a good drag race or nice sweeping corner. I don't have the restrictive stock exhaust so I have it jetted a little rich on the top end.

 

I don't know enough about lead to say anything, but I would think the bike is designed for use without it, and it could be excessive and hurt the motor. Just my guess.

As for the flames, all I did was explain what causes it, and with a STOCK exhaust system and jetting it should never happen.

 

I had a '64 Corvair that I had to add liquid lead to because of the age of the vehicle. Vehicles now are made for unleaded gasoline. They made the valve seats harder so there was no need for the lubrication the lead gave in gasoline.

Paint hit what my boyfriend was trying to tell me. So I figure why not put the cheapo stuff in it.

My van on the other hand hates 87 and I have to put mid-grade in it. The owners manual even says 89 octane or higher.

 

As cars age and the valve wear, you up the octane to avoid knocking. (detonation.)

 

I started out using regular (87) and it ran fine, but it had a funny vibration at certain RPM's. I was once told that in 1981 regular gas had a higher octane rating than it does today, so if you run mid-grade (89) it will be closer to the original fuel. I tried it, and the engine vibrates much less than it did. Sometimes it starts a bit hard when warm, but overall it runs very nicely. Your results may vary.

 

This is interesting because my bike too has a funny vibration around 5-6k. It's not real strong or anything, but the bike is so smooth everywhere else that even a small vibration is noticeable.