Fuel: Regular or Ethyl

I have an 1982 XJ 750 RK Seca. I have been told to use premium fuel as the engine was designed to use leaded fuel that is no longer available. For price reasons, I would rather use regular gasoline, but the octane is only 87 in California and I don't want to put up with pinging and the resulting possible engine damage. It would be great to hear some comments and thoughts.

 

I run 87 octane with no problems here in west virginia.

 

What kind of mileage do you get on the 87 octane?

 

I run 87 out here in SoCal with no problems myself. Currently I get low to mid 40s for mileage.

 

Yeah about the same here. I average 35-40 MPG. It all depends if i can stay out of the throttle. :roll:

 

Just because these bikes were built in the end of the leaded gas era, doesn't mean that they need the lead. And the connection between leaded gas and premium gas boggles me. Today's premium gas has at least 2 octane points more than yesteryear's gas. Our regular gas 87 octane (89 in some areas) is two point greater than the 85 octane of my youth. Lead was only added to boost octane and engines were built around it (mainly with regard to valve seats). Once the lead came out, there was some indication of increased valve seat wear so auto manufacturers switched to hardened valve seats (which definately increased durability of the motor).

Now, back to your original question. Ethanol was added to gas as part of the EPA's Clean Air Act (thank the Clintons for that) (MTBE was also used but found its way into the groundwater readily) as on oxygenator since ethanol has more oxygen by weight with a chemical formula of C2H6O compared to gasolines approximate C8H18 (octane). Gasoline is a mixture of different hydrocarbon molecules ranging from C6H14 (Hexane)to something like C12H26. Older gas (from the 60's on up) probably had more heavy molecules which should have resulted in a higher energy density (great fuel milage).

Anyways, regular gas is fine all around the country. This has been hashed out a couple times now.

 

Thanks, I will try 87 octane next tank and see what it does to my mileage. I have been getting over 50 so hopefully, it won't affect it much.

 

I find that my bike runs more smoothly on 89 octane.

 

I'm not running Regular. Too much of a percentage of ethanol in it for my tastes. The exhaust is heavy with moisture and thats not good for the exhaust collector.

I give the guy 10-Bucks and Pump 5-Bucks of High-test and 5-Bucks of 89.

My bike is running GREAT!
If I run Regular ... I can hear the pinging.

And, ... that ain't opportunity knocking!

 

Thanks All,
I am going to try the 89 octane with the next fill up and see what happens. I don't think we use ethanol in the fuel mix out in CA, but I am not sure.

 

Some of our stations have ethanol mixed with the mid grade and premium fuel. I run regular all the time and the bike runs good and gets 45+ MPG.

 

FYI; ran 530 miles on regular gas and averaged 50.6 MPG. Bike burns regular fine.

 

Funny, you'll produce more water burning pure gas than you will with an oxygenated blend...assuming that you are running at, or near, a stoichiometric air:fuel mixture. Plus, once you get the exhaust up to temp, you won't have to worry about any water collecting in there.

Here in the corn (rust) belt we don't have a choice since all gas has 10% ethanol blended in it which by the way has an octane rating of about 108. But if your engine tends to knock with regular gas (which means you might want to check your heads for cleanliness) then upping it a grade does make sense.

 

From what I understand about the issue, regular vs premium, it all boils down to how you ride your bike.

If you like to gun and go use premium and you will get the most out of the engine with no bad side effects. If you don't then burn whatever.

These engines at least the 1980 version where built to run on 91 octane.

 

The best thing to do is experiment.

Find out what works best for riding YOUR bike, YOUR way.

If you feel that you get better performance, mileage, prestige, etc, by running premium through it, then by all means do so.

If you are like and bought the bike to have fun, save money, pick up chicks, then use regular.

Actually, what I find that works for me is that depending on how I plan to ride it, I will use different grades. For commuting, I use regular. When I am going on a long cruise like Mn-Maxims and PainterD and I did this past weekend, I used mid-level.

The weekend prior, when I was riding on some twisty turnys up in Brainerd, then I ran premium as I was on and off the throttle a lot.

Depending on how I ride, I get anywhere from 35 to over 50 mpg.

Since the bike holds around 3 gallons, and with the range in price between regular and premium being 20 cents, you are only looking at 60 cents more for premium. If that much.

Dan

 

You have your answer on fuel octane rating by now, but just had to comment on your beautiful Seca - love the luggage setup.

 

I get 45-50 mpg, when I do not take the highway. and right at 40-45 when I use the highway, I only go a few miles on it though. I run the reg. gas. I notice some sputtering at top end but I know my carbs or something needs adjusted for that.

I have found a few gas stations that advertise NO Ethynol! They are mostly mom and pop stations but some larger ones here are posting it on the bright flashing LED signs in front. I can notice a difference when I use the ethyl fuel vs. the reg. fuel. It costs a few pennys more but considering that ethyl can damage petrol based products it is worth it. ( Ethyol is a corrosive to plastic, rubber and opther petrolium products. )


A local news station here ran a story on ethyl and it is causing kind of a backlash. The mom and pop stations are seeing a large increase in sales. You get more energy from non blended gas, there for your fuel economy higher. They did a test and found that they lost about 30% fuel economy on their TV station SUV's.

 

Were they talking about E-85? That does get about 30% less mileage and up here in Rusty Corn Belt, the price is about 30% less than regular.

Ethanol does have a much lower energy content, but, it does have a higher octane rating. Most vehicles made since the introduction of the catalytic converter on cars, have been designed to run with up to a 10% ethanol/gas blend.

With the introduction of E-85, more cars are coming out that can run with that much alcohol in the fuel. I don't know of any bikes that can handle that much alcohol without a lot of retrofitting of parts. Even if they were available.

Just an FYI, Ethyl usually refers to Leaded gas. Ethanol is the alcohol that they put in gas to increase the octane rating by oxygenating it. And, it is also the alcohol that you put in your body when you drink beer. It is made from grain.

Methanol is also sometimes used as an additive to gas. It is referred to as MTBE or even wood alcohol. This stuff is toxic to most things, especially humans. This stuff is very corrosive to auto parts not designed for it.

Ethel is a girl I dated in high school. And when you put ethanol into her, well, she definetly go my motor running. But, that is another thread.

 

Thanks for the thumbs up, smeghead! Yes, I got my answer, and I do notice a couple of MPG difference between 87 and 91 Octane. I will use regular on the road and premium when I am riding in the twisty turny's (high country) or when I have a passenger. As someone pointed out, it is less than a $1 difference per fill up.

 

If your bike runs without engine knocking on regular gas, there is no need to use premium.

Also, you can run lower octane fuel at higher elevations. Around here all regular gas is 85 octane.

I use regular in my Seca and premium in my R6 because those are the recommendations of the manufacturer.

This link gives some interesting facts and dispels some myths about premium gas.

http://www.state.mn.us/mn/externalDocs/ ... eFacts.pdf