Premium or Regular Gas

[clarky711]

I have a 1959 35HP Evinrude Lark that I've been working on. I hope to get her running this weekend and I was wondering if you guys recommend the reg gas or if you use premium gas? I always use prem. in my snowmobile, but I'm not sure if I should with the boat? Thanks.

- Mike

 

[tashasdaddy]

Re: Premium or Regular Gas

it will be very happy with regular unleaded, and a mix of 24-1.

 

[JB]

Re: Premium or Regular Gas

In 1979 leaded gas was the better option. It had nothing to do with lead; it had to do with octane. The unleaded "white" gas of the time was only 80 octane.

Thirty (30) years later leaded is not available and unleaded regular is the best option.

 

[tx1961whaler]

Re: Premium or Regular Gas

My '79 Chrysler 70hp factory User Manual, REQUIRES leaded gas. It states, and I quote, use unleaded gas "only occasionally".

Where can I go to verify the information that these older engines will be "very happy with regular unleaded"??????

Thanks

You posted this 3 times in 2 different forums. EXTREMELY bad form.

Q - What grade of fuel should I use in my motor?
A - Current recommendations are to use a minimum of 87 octane, 89 octane is preferred. There is no additional benefit from using higher-octane fuels, in fact they may cause hard starting conditions in hot weather. If you have an older motor and the owner's manual requires premium fuel, here's why:
When these were built, the best oil available was TCW-2 rated, and did not contain the additive package (detergents, carbon preservatives, etc.) which our current oils (XD-30, XD-50 and XD-100) contain today. In that era, premium fuel contained the additive package that helped prevent the formation of internal engine deposits. That's why premium fuels were preferred at the time. Ultimately, in the late 90's the federal government mandated fuel refiners to use the same additive package in all grades of fuel and the premium fuel requirement was dropped.

evinrude.com