High Grade Fuel
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Using anything higher than the recommended 87 only costs more and gives nothing back in return for the extra money spent. 87 all the way for me !
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4,151 Posts
There is quite a bit of chat on this topic here: Gas Mileage and more on why high grade only refers to a higher octane number and not quality: Fuel Grade Tech
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200 Posts
I run 87. The motor in the Fury doesn't have high compression so you don't need a high octane fuel.
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Yep, but the slower burn is more complete, the faster burn tends to leave behind carbon which builds slowly but steadily, causing you way more problems in the long run. Some may never have an issue, but if you're going to have a nice shiny motorcycle on the outside, why have a nasty mess on the inside? 87 is for burning trash. Just for the record, 93 octane and Mobil1 20w50 synthetic is the only mine will ever see as long as it's mine.
Harley Davidson always says to use the high grade gas. My Fury dealer told me to absolutely use 93 grade in the Fury but didn't really say why.
The lower grade gas is more volatile and takes less spark to ignite it. This is good for starting in cold weather. However the trade-off is that it doesn't burn as clean and therefore is prone to cause buildup of crud on intake valves and exhaust. Lower grade gas leaves more black carbon deposits in the exhaust opening where the 93 does not. Maybe because of the higher octance or the addtives. Not really sure about that. It does the same in my car which is a Honda also. The car has significantly less pulling power with the 87 gas. Bike seems the same power with either.
The lower grade gas is more volatile and takes less spark to ignite it. This is good for starting in cold weather. However the trade-off is that it doesn't burn as clean and therefore is prone to cause buildup of crud on intake valves and exhaust. Lower grade gas leaves more black carbon deposits in the exhaust opening where the 93 does not. Maybe because of the higher octance or the addtives. Not really sure about that. It does the same in my car which is a Honda also. The car has significantly less pulling power with the 87 gas. Bike seems the same power with either.
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4,151 Posts
First off, if you have single wall chrome pipe (and we all know that you do) it will eventually be blue, bronze and chrome in that order from the exhaust port down. That's what happens when ya gotta take the heat. Double wall pipes hide the heat discoloration.
Regular fuel is like Classic Coke; it's the original. Well not quite; it's sugar/lead free.
Premium fuel was developed for engines that operate at higher combustion pressures (not necessarily higher compression ratios). Theses high pressures cause regular fuel to burn too quickly (higher volatility) so they added a little "molasses" to make high octane gasoline burn slower, control the pressure rise and prevent detonation or "pinging". Temperatures are only higher due to higher pressure, not the fuel. It actually runs cooler in the Fury but no, it won't stop your pipes from blueing.
So it would appear that you get more bang for your buck with regular in your Fury. Yes Virginia, there is a Santa Claus!
For a more technical exposé click here.
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the hight octane is more stable so it won't pre-ignite when you have lots of compression. thats why the old cars needed to have that higher octane. most newer motors are designed to work efficiently and have low compression ratio which run perfectly fine on 87. there is a Chevron refinery that has a testing facility that I have some interaction with. from what I understand any of the brand name fuels have all the additives that help give you a clean efficient burn.
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Garc,
Thank you for the wealth of information. One question - the manufacture of the new pipes stated I should not install them until I have installed a fuel controller... I am just wondering why not having the FC will have such an impact on the pipes chrome? Since the engine would be running lean = engine running hotter with the new pipes; will the additional increase in temp be that much different?
In advance, thanks!
T
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4,151 Posts
It's all a question of degree ~ pun intended.
Your pipes are going to blue regardless but I expect less with the controller since as you say, they should run a bit cooler. How much we will never know 'cause I doubt you'll get to try it both ways with a fresh set of pipes. Even so, with different riding conditions results will vary on each application.
Also, the amount of baffle may have an effect. I don't know but I would expect an open pipe to release the heat sooner and reduce bluing provided you and your neighbors enjoy the noise. It can be painful to ride beside a buddy's open pipe.
If you are chafing at the bit to get your new look and sound you could ride very gently until the controller arrives and possibly
not
I would jump in there and offer an answer for ya but then Cycho would book-argue with about 3 million words thrown against what I've found in my experiences with V-twin engines and then ending with "well probably we basically agree" or some such other stuff...heheheheh. You may have read already, I installed the V&H Cruzers almost 2000 miles ago (did no airbox changes Cycho) and driveability is FINE, no back-fires, no lean conditions shown, plugs look good, and NO BLUING. Granted, this is one motorcycle, and one particular set of pipes. But there are variables so don't just run up to the cliff and jump off; follow up for a while. Point is, my exhaust change not only worked (no lean conditions), it worked as expected (due to no air-box changes), and I kept a close eye on it the first few miles to make sure there were no lean conditions (driveability, plugs check, etc.). If you follow this course, you'll be safe from doing damage. And as Garth said, you will get some discoloration, regardless of how "fat" you make the mixture. And as an aside, every bit of fuel you add to the mix also (in addition to some performance improvement) also takes away from mpg. Find a good compromise!
Using higher than needed is wasting money and usually results in incomplete combustion. If you ever saw a head all carboned up from unburned fuel you might form a different opinion.
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