What kind of gas do you use?

Further to Mike and Stuke, and also further to what I had said. I do know that years ago I worked as a petroleum, transfer engineer, back when we had such an animal. In Winnipeg, there were two refineries. I believe they were Shell and Esso if I am not mistaken. ALL the gas sold in the Winnipeg area came from one of those two refineries regardless of the name of the station, including mine which was Gulf, later to become Petro Can. For that matter, I think all of Manitoba was supplied from those two refineries after the refinery in Brandon shut down in the early 70's. The only exception to this was Mohawk which was a Canadian Petroleum company that sold blended fuel back when no one knew what it was. Theirs I believe was trucked in from Alberta. So all said and done, stations with high turn over is more important that a station with a particular name, here in Canada anyways.

 

Mmm yea there's a Diff, But probably on a 6th gen it's not noticeable, as those have all the electrical giggie gadgets that make it work. On thy Carbed machine it's really noticeable down low, especially when she idles she runs way smoother, also Noted on some other machines on a dyno you do get a better HP curve, some not as much as othersthou so it's different all across the board. I was told by said dyno tuner Mike Valasco if I was to run 105 race fuel, I'd see at least another 5hps, so you tell me if it does anything?

 

well in my, i run shell 93 octane, the bike runs smoother and gets better milage

 

While stale gas is a possibility, I don't think this is the case. Same with the fuel filter. I would be more inclined to think it was water (or something else) in the fuel that my truck didn't like. As soon as the Chevron gas got mixed in, everything was good. No problems since. I had a road trip from Ventura, CA, to Las Vegas, NV, where I got the Rebel gas, to Mesa, AZ, then back to Ventura. I got the 89 in a little town on the 93 in northern AZ, and when I reached Wickenburg, everything was good again. The only thing I can think is that it was the cheap gas from Rebel.

Thanks for the thoughts. I know the filter is good, changed late last year.

Mike

 

What's that smell?

I tend to be very aware of the odor of my vehicles' exhaust fumes, be it my '03 Toyota V8 4Runner, or my '07 VFR. It just seems intuitive to me that a good quality, clean fuel ought to have an inoffensive and rather pleasant exhaust aroma.

On the other hand, if I purchase a tank of fuel and I soon smell the unmistakable stench of a high sulfur content in the fuel, which smells rather like rotten eggs (or perhaps dog farts) I will avoid that brand and/or source of fuel if possible.

The chronic use of fuels with high sulfur content can't be good for most catalytic convertors. Moreover, the exhaust odor from such swill is absolutely nauseating, and the sulfur compounds in the exhaust may quickly bring on coughing, sneezing, wheezing, watery eyes, headaches, and so on.

If you've ever been unfortunate enough to fill-up with a batch of high sulfur fuel, and you then switch to a low sulfur and cleaner burning fuel, the sulfur stench may linger for quite a while, since the cat. convertor has been tainted.

At any rate, 12 oz. of Chevron Techron Concentrate added to a tank of fuel every 3000 miles is a good idea.

 

I have to run 91+ octane in my 83. I think it states that in my owners manual. My static compression ratio is stock 10.5:1. My timing is fixed. By that I mean there is no ECM (computer) to control timing (plus fuel). I don't have any specs on the stock cams(lsa, dur or lift) so I don't know what the dynamic compression is. What ever it is it requires high 91+ octane to keep away from detonation. Remember the higher the octane the slower the burn.

The dynamic cr is what controlls what octane you need to stay away from to keep out of detonation. The higher the DCR the more octane you need. DCR can be controlled by the cam profiles. Not really the best way to do it, but one option. The less total mechanical spark advance the lower the octane you can run (basicly) with same DCR. Temp of motor(combustion chamber temp), A/F ratio and load on motor are some of the other options.(band-aids)

If your motor was designed to run on 89 octane, then 93 octane will not help you produce more power. It may even slow you down some. With computer controlled engines. The timing is controlled by a knock sensor. If the sensor starts to detect detonation(knock) it will reduce the timing. The motor should run fine and no knock is heard. But it will not be making optimum power. You may or may not feel it in the seat of your pants. Only track or dyno time may show you.

Those of us with classic cars w/big old V8's in them have played this game for years in trying to keep motors together and still have max power on the street with todays gasoline. Additives are not welcome. if they are that good the refiners would be using them. Most are just snake oils for the most part. As far as paying the high price for dry gas. Use isopropyl alcohol. It will mix the gas and water together so it burns in the motor. Some dry gas just breaks it up in to smaller parts and keeps it separate.

To find out more about DCR Dynamic CR

To figure DCR Wallace Racing: Dynamic Compression Ratio Calculator or http://www.smokemup.com/auto_math/dynamic_compression_ratio.php

So if your motor was designed to run on 89 then higher octane won't buy you anything. Lower octane will put you down on optimum performance.

more info at Fil's Auto Corner: Gasoline FAQ

If you mix different octanes how do you know what you actually have? That's easy to figure out. Lets say you have a 20 gallon tank. You put in 10 gal of 87 and 10 gal of 93. Multiply 87x10=870 then 93x10=930 add together 870+930=1800, divide by 20 gal 1800*20=90 octane. That's what you have in you tank. 90 octane fuel. So if you need 89 octane and you can only get 87 and 104 race gas you would need 16 gal of 87 and 4 gal of 104 to get an octane rating of 90.4. Which meets your 89 octane needs.

It doesn't matter to me what gas I use as much as what octane it is. Besides you don't know for sure what your buying now a days. Most companies get gas from each other when needed. So you could go to a Chevron station and get Shell gas or some mixture there of.

Hope this helps.

 

I have done a mini experiment running the same length of road at various speeds and rates of acceleration based on throttle position. I've found a significant difference between running 87 and 92 octane fuels, but I really only feel it when the VTEC kicks in at high RPMs. (I'm on a 2005 btw).

The normal around town driving isn't much different, but when i'm running 92 vice 87 and the VTEC kicks in while I'm on the gas, there is a very noticeable difference in the rate of acceleration. I would guess that the VTEC affects compression in some way, and I've noticed the higher octane makes a difference under those conditions. Just my non-scientific observations... but science is observation, so you can trim that how you want it.

Just my 2 cents.

 

It's the whole "A square is a rectangle but a rectangle isn't a square" thing.

If your engine is designed to run with 87 Octane, then using 92 is a waste of money and you will see no performance benefits. HOWEVER, if your engine is designed for 92 (and equipped with a knock sensor) then you CAN run 87 Octane but will see decreased performance due to computer using a non-optimum timing process. You WILL see MORE performance from 92 Octane in an engine that was designed to use it.

The most important thing you can do is read the manual documentation. There are two key words to look for, "Required" or "Recommended". These are industry standard terms that mean the following:

"Required" or sometimes "Only" -- "Use Premium fuel Only" or "Premium Fuel Required". This statement means that you MUST use premium fuel or risk damaging the engine. This is usually only found expensive cars or very high-compression, lightweight sport engines (usually).

"Recommended" -- "Premium Fuel Recommended" or "Use of Premium Fuel is Recommended". This means that the engine was designed for the use of Premium fuel and you will in fact get improved performance out of the engine by using it. However, the engine is of such design and engineering as to accommodate the use of low/standard grade fuels. This statement usually means the engine is equipped with a knock sensor to detect pre-detonation and the computer will adjust the timing to account for this problem.

 

fuel octane

1984 vf750f canadian version manual says octane 86 wonder why difference,us model maybe detuned somewhat ?

 

I've always put 87 octane in my '04, per the manual. I don't stick with any one brand, but most of my fill-ups are at Speedway or Marathon, sometimes BP or Sheetz, too.

The only additives I've ever used are SeaFoam every 3k-5k mi, and Stabil when I winterize the bike.

BTW, when I considering trading/selling my VFR for a BMW K1200R Sport last summer, one turn-off was its spec'd min. 90 or 91 octane requirement. Just another factor to consider when thinking about a new bike IMO.

 

i used 93 octane on my 87vfr. i find it runs more powerfully with perium gas from shell or bp.

 

I like clean valves... Chevron with techron or Shell V Power, last time I had the carb off my XR650R 15000 hard on / off road miles, the intake valves were shiny zero carbon deposits, check your valve stems (carbon blobs) running cheap fuel.

 

I use the cheapest thing i can find. my 05 and 00 vfr's have run flawlessly on anything I have put in there.Never could tell any diff from any kind...stockers

 

I live in Minneapolis. My local Shell carries 91 non oxygenated so I'm lucky. I fill up exclusively here but if I'm on the road, I have no issues going anywhere. Most gas comes from the same refinery with slightly different detergent packages but these days, the quality is much better than it used to be.

 

This thread is full of more misinformation than I can believe.

Let me just state a few facts.

1) VFR's do not have knock sensors. Show me the part #? Where is it located?

2) VFR's are designed to run on 87 octane gas without pinging/preignition.

3) Because the FI bikes do not sense knock, there is simply NO WAY the FI computer can alter timing/etc in order to make more power from higher octane fuel. If you "feel" your bike makes more power with higher octane fuel, you are simply living proof of the power of suggestion.

4) I have a very good friend who is a regional manager for Exxon/Mobil, in charge of 100's of gas stations. He gets his gas from the same pipe as every other gas station. The ONLY difference between brands is the additive package. Period. And those differences are mostly marketing hype, you're lucky if the guy adding the additives is even doing it correctly.

 

I'm not going one way or the other, just saying this:

I had a zx10r ninja that was a factory race bike. It had been retired, and years later I ended up with it. It was carbed of course, and if I ran 87 octane, it ran great! 89, no difference. 91, picked up .2 on the drag strip. 94, gained .4 over 87. Ran 106 race gas that was available at the drag strip one time just wondering what it would do, and ended up going .6 faster than 87. Not saying that all of this was due to the higher octane each time, as i'm smart enough to know that humidity, temperature, barometric pressure (or the density of air however you wanna look at it) all play into overall times. But, the environment couldn't have been the only reason my time slips improved over the weeks tested. From then on out, I always carried a spare fuel tank with me. Ran 93/94 on the street, and when i took the bike to the track, always swapped tanks, ran the bike til it ran out of gas, then filled with 106, then just reversed when i went home.

On my VFR, when the guy delivered it to me, he had a tank of 87 fuel. I asked him what he ran in it, and he said never more than basic fuel. I ran that tank until even reserve was out, riding it hard to get baseline results from it. Then filled back with 93, and it DID run better. Crisper response, more power thru the band, and faster revs from take-off to redline. Also with the higher grade gas, the front wheel was more apt to come up on me. With the 93, it felt alot more like the true sport bike it was designed as.

 

87 in the VFR and at least 91 in the Buell,, Buel has a higher C/R.

 

If you really get into the science of fuels, particularly the race fuels, there are differences between how fast they burn and energy content etc. Sometimes you can get a small amount of power increase by matching the fuel to the engine and making small adjustment to timing to account for the different burn rates.

However as a very general rule "premium" pump fuel actually has slightly less overall energy content than regular. This is because the low-octane component's of gasoline usually have a higher energy content. Picture kerosene (low octane) vs. ethanol (high octane).

Also, one way to achieve a high octane rating is to tailor the components of the fuel to achieve a slow burn rate, which reduces peak pressures in the slow-reving test cells they use to measure octane and hence resists knock. However throw the same fuel into an 11,000 RPM motorcycle engine and that slow-burn will work against you.

So unless you are doing the dyno runs, tuning your engine to the fuel, and always buying from the same exact source, you are 95% of the time actually better off with the lowest octane your engine can safely run.