RatFink328

Owners, what are your experiences with different grades of gas? Is there a certain grade that the bike runs best on?

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Buickguy

The Rebel runs just fine on 87 octane.
No need for anything higher. There are no benefit to higher in a Rebel.

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1987 CMX250C Rebel

2002 FSC600 SilverWing

1983 Yamaha Midnight Virago XV920MK

Put your bike's year and size in your signature.
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RatFink328

I just wondered. Ive had a few 4 stroke Honda 250cc dirt bikes that liked premium a lot more than they liked regular.

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socalmarcus

I run 87 in all my bikes, works fine.

Although there are other factors, the Rebel 250's 9.2:1 compression ratio shouldn't require anything higher. I'd guess anything below maybe 10:1.

I think the 'use the lowest (and therefore less expensive) that works' is a good rule of thumb. Just another opinion though.

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'07 VN900 Classic
'99 Rebel 250
'73 XL 175

Fridgitator

I run regular, as recommended in the manual. I'd use Regular regular, with no ethanol if it was available here. I haven't seen it.

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twocoolgliders

Yes, compression is a factor in what octane is needed but also piston size....the smaller the engine, the higher the compression you can have and still use regular.......ignition timing also plays a part.

My scooter, 125cc is over 10 : 1 compression but used regular.......

Cookie

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JunkyardDog

Regular 87 octane unleaded "pure gasoline" is what is "best" for the Rebel, unfortunately, that is not available around here. All we have is the crap with 10% ethanol. This stuff gives you approximately 10% less gas mileage, making the gas cost 10% more, it damages the fuel system, and is not great for the valves. It also causes a slight power loss.

There are a lot of things that affect the type of fuel an engine runs best on. Compression "ratio" is only one of them. True compression in the combustion chamber is another, engine temperature, piston diameter, how far the piston goes up and down (bore and stroke), air/fuel mixture, valve timing, cam lift and duration, ignition timing, intake air temperature and density, engine speed, gearing (yes, if you put to much of a load on your engine by lowering the gearing too much, you will need higher octane gas, and probably new crank and big end bearings in the not to distant future). There are more than 20 different things that affect the octane rating a specific engine needs. Jerry.

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twocoolgliders

Right.......Now you plug in all of those parameters, and what comes out?

87 Octane!

The Manufacturer will spec out the gas to use. Regular fo the Rebel, and most of the cars on the road today......

Cookie

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maxweljames

New member here, thought I might jump right in to the deep end of the pool. As a younger man I had access to some really high octane stuff(with a little bit of lead added in perhaps) But I found that about 1/2 tank of 87 unleaded mixed with the "good stuff" would give me superb performance, absolutly fantastic. It was fast, quiet, smooth, ran a little on the hot side to what I felt was normal. And that 250 rebel ran for a couple years with that type of mix. And it ran for years after going back to straight 87 unleaded. So additional pep is possible with a stronger brand of coffee, but certainly not required.

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jax

My 450 seems to run better on 91 Octane. At the most it costs about 60 cents more to fill it with fuel. Seems to get better mileage also about 65 mpg instead of 62 not much of a difference but I like the better performance.

Ride safe

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