Fuel type (regular or premium)

[Patboy]

Hi, I just bought a used Tige 21I 2002 and try to know which type of fuel is better or I'm supposed to use for the boat. The dealer said I can use regular but my neighbor said I'm better to use premium or super. What do you think about this? Thanks for your help!

[da.bell]

Regular gas is just fine. You won't see any performance increase between the Premium compared to the Regular gas.

[samw]

I use regular

[murphini]

My owners manual says 87 octane.

[dogbert]

Regular gas, but watch the ethanol content. If you don't use your boat all that often, use some Stabil or equivalent.

[brett22i]

Regular gas, most engines specify 87 octane because they are tuned to burn that octane. Using higher grade would be a waste of money and no major benefit in hp gain. I have heard that you could have someone program the engine to use a higher grade and this would benefit in a horsepower increase, but there is a big difference in cost when running high test.

[chpthril]

An engines recommended Octane rating usage is related to the engine's compression ratio. Engines with higher ratios build more heat in the cylinders during the compression stroke. Higher octane fuels are blended using a ratio of Heptane and Octane, in order to resist igniting early due to the increased heat. There is absolutely NO performance gain in higher octane fuel, they contain the same BTU's/Oz as 87oct. On the other hand, Ethanol blended fuels have less BTU's then non Ethanol.

Save your coin, use what the engine is designed to use, 87oct.

[gman]

Use 87 Octane. Use stabil when you are putting boat away so that the gas especially with ethanol mixture does not degrade.

[Thomas Hohl]

Huge problems with the ethanol here in Texas. Especially on smaller non-fuel injected motors. The ethanol causes white powdery residue to plug up the jets. Ask any motorcycle service department in town and they will tell you that they are getting rich rebuilding carbs because of the ethanol. I would definitly add Stabil to my fuel when I store the boat.
One more thing the oil companies aren't telling us...

Just my

[andrzej77ff]

I bought an 03 21i about 2 months ago and the previous owner said all he used was premium, so that's what I've been using. Would it be a bad idea to switch to regular now?

[dogbert]

No, you should be fine. My boat actually runs better on regular gas. Just make sure it's good quality gas.

[chpthril]

No, you should be fine. My boat actually runs better on regular gas. Just make sure it's good quality gas.

X2

[Joeprunc]

Crap...I'm running 92 Octane. I'm assuming my 350 Chevy has the close to the same compression ratio as the newer motors. But since mine is carbureted, I wonder if that makes a difference.

[SPBFAN]

One more thought for this topic. The 91+ octane fuel is generally a lot more expense so the fuel stations do not sell it out as fast as the 87. As a result the fuel sometimes gets taken back by the fuel supplier or manufacture because it will go bad before they sell it all. They do not add stable to it at the station. The big question is did you buy the fuel right before they took it back and get some bad fuel? I know KONA here on TO did this and he had all kinds of problems until I finally asked the key question about the fuel in his tank. He drained it went and filled up with 87 and his problems with an injector cleaning went away.

[SPBFAN]

Crap...I'm running 92 Octane. I'm assuming my 350 Chevy has the close to the same compression ratio as the newer motors. But since mine is carbureted, I wonder if that makes a difference.

Here in CA you need to buy the cheap stuff. 87 octane. We even run that in our BMW. It says to run premium fuel. CA. lowest grade is a premium fuel because of our emission laws.