I know, its a topic beat to death. I have a question because every thing that I have seen about oil are like if you ride in 80 degree and hotter heat use this weight. If you ride in 50 to 70 degree use a lighter oil. You guys know what I mean. I was wondering though, since the temperature is so different around here, what I should be using. Like today, its gonna be 90 degrees out, but tonight it will be around 60 degrees out. I want a thicker oil to take the 90 degree heat, but don't won't one to thick for 60. Will it really make a difference with it only getting down to around 60 though, I mean if after the engine warms up it should thin it out enough if I get a good oil with a broad range right?

Well, what thickness should I be using? 10w40 seems to thin, but 20w50 seems to thick.

 

I've been going thru the same dilemma. Here's what I've learned:

1. 10W30-10W40 is good ALL-AROUND oil from freezing to 80 degrees F
2. 15W50-20W50 is good for 40 degree and much higher temps, and may be the better choice for racing or hard riding in summer months.
3. *Fully* synthetic oil CAN cause some slippage in the clutch.
4. Regular oil changes, based on riding conditions and frequency, no matter what kind you use, is the best thing for a car, ATV or any kind of combustion engine. However, synthetic-blend oils will last longer.

I was going to start using only Mobil-1 (as I do for my car), but, after reading 2 or 3 mag articles about 100% synthetic oils being VERY GOOD for internal engine parts, but causing slippage in clutches, I am going to stick with Synthetic/Petroleum blend 4-Stroke oils.

Interesting tidbit: Honda's new CR450F has SEPARATE oil sources for the engine and for the clutch. Why? They want the slipperiest stuff available for the engine (100% synthetic), but they need something less slippery for the clutch....that speaks volumes to me.

So I now use only Synthetic/Petroleum blend:
10W30 fall/winter/spring
20W50 in the summer

My .02

 

Thanks for your $0.02, it is kind of helpful.

Its just cornfusing to me when I try to figure out what to use. Like I say, all summer around here the temp is between 60 and 70 every night, then during the day its anywhere from 80 to 100. I guess I'll go with 15w50, seems like it should be ok. I don't really ride my quad hard, but due to the nature of the trails, lots of good looong hillclimbs, and slow muddy stuff I think I'll want something to take the heat better. Then at night I want something that won't be to thick. It would be easier to figure out if I rode daytime more, or night time more, but I ride them pretty much equally.

Thanks for replying.

 

I use Castrol Syntec 10w-40 and it makes the clutch slip some but the clutch pull is so da** easy its pittiful! OMG that thing is easy to pull.

 

You have to be careful with how much slippage synthetic oil causes...
It can lead to premature clutch wear.

 

i run 20w-50 castrol motor oil, this is a good oil to run if you live in a hot place and ride your atv hard.

 

Okay everyone. I started running synthetic Honda HP4 oil after I got my motor work done a few weeks ago. What do you think of this oil?

What oil do you suggest for great engine protection, but no clutch slippage in my 400EX that is used in very harsh, hot MX racing? I want to hear from everyone that has an opinion. Thanks a lot.