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Author Topic:   oil weight
Dirt Maniac

Total posts: 106
posted April 07, 2003 01:05 PM
If you where going to be running in 45-55 degree air temp what weight of oil would you run.Been running 20w50 val until broke in then 15w50 mobil 1 1st race is this friday eve and it snowed today and is supposed to snow tomorrow and be about high of 50 friday.should i run straight 30 until its warmer?

Dirt Forum Champ
Total posts: 620
posted April 07, 2003 01:45 PM
your 15w-50 mobil 1 will be fine. i might be mistaken but i believe it's thinner than straight 30 weight. be sure to let the engine warm up completely before you race.

[This message has been edited by outlawstock17 (edited April 07, 2003).]

Dirt Freak

Total posts: 353
posted April 07, 2003 02:07 PM
I think as long as you let it warm up good before you start pulling on it you would be ok with either. Dont just start it up and hit the track... get some heat in it and get the oil warm first.

Dirt Forum Racer

Total posts: 91
posted April 13, 2003 01:19 AM
Some may tell you different. But the first number that has the w like "15w"-50 is the actual weight of the oil. The second part 15w-"50" is the lubricating specs for the oil at operating temperatures. 20w-50 is actally lighter wieght than straight 30.

Dirt Freak

Total posts: 353
posted April 13, 2003 07:40 PM
That is correct the first number like 20w in 20w50 is the actual weight of the oil but at 100 degrees celsius it will have the viscosity of a 50wt oil at that temperature. A straight 30w oil will still be 30 wt at 100 degrees celsius. So the 20w50 will lubricate like a 50wt oil at operating temp but flow like a 20wt when cold.

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