Automotive or Motorcycle Oil?

Are there any negative side-effects of using automotive engine oil in a motorcycle? I was told today by someone that using Castrol 20-50 automotive oil could damage internal engine parts.

Whoo hoo! An oil thread! :laugh:

Seriously, the advice I've read is to stay away from friction reducing additives which will purportedly ruin the wet clutch. Most anything should be okay so long as it doesn't say "friction reducing" or some such. By all means, stay away from Slick 50.

My thought is that regular automotive engine oil should perform well unless operating the motorcycle at a heavy load. Under those conditions I would be concerned about "gear shear" in which the high pressure area of the transmission gear teeth can destroy the polymers in the oil.

All that said, I am running Castrol Act-Evo 10W40 in my bike and this past oil change was very clean which was the second batch of Act-Evo I ran through it. That is a motorcycle specific oil that is a partial synthetic blend. I will say that I noticed a distinct improvement in the smoothness of gear shifting within a few miles of putting in the first batch of Act-Evo. I was able to buy it at the bike shop for $4.75/ltr this summer. It's not cheap, but I think it offers excellent protection for my bike and that is what matters to me.

There are a large number of us running Shell Rotella T diesel engine oil

I've been running Castro GTX 20w50 in the wifes VN750 and both of my bikes for quite a while now, and haven't had a lick of probs.
I may switch to 10w40 on her bike though.
She doesn't run her bike as hard as I run mine, which certainly can benefit from the added bit of cooling/resistance to viscosity breakdown protection offered by the 20w50. :whistle:

I ran Castrol GTX for the entire 160,000+ miles on the KZ650. Last time I went to drain the oil it was all sludge and would not drain. The engine was clean up until the last few oil changes. I have question whether the formulation of the oil was changed where it was no longer usable in a motorcycle from this so I won't use it. Probably just a worn out engine, but the same idea as when you get the flu you always think of the last thing you ate as being what made you sick. This engine got real sick on Castrol.

del

I've been running Castrol 20W50 in my bike for 4 years. Never any sludge, shifts smooth. Oil is readily available at local Wallyworld at a great price. Change it frequently, DON'T use those "orange" filters.

I run the cheapest SAE oil I can find. Never had a problem. Ditto for my truck which has 250k miles on the engine and plenty of oil pressure. I also use the cheapest oil filter. Change truck and bike oil every 3000 miles or 6 months, whichever comes first. Sometimes diesel engine oil is cheapest. It works fine in the truck and bikes too.

Gotta get back to changing plugs on the truck. 50k miles on them and the gaps have grown fat while the bent electrodes have grown thin...took a break with KZR before attacking the two 'difficult' plugs.

I hate to add to an oil thread but I have 12 quarts of Havoline 20w/50 and when my kz550 comes out of storage next week I intend to use it. Before storage I did an oil change with castrol gtx 10w40 and rode it just long enough to get the oil warm and the fuel stabilizer through the works.

I don't want to run the 10w40 for long but all these oil threads have me spooked. I'd like to run 4 cycle bike oil but it's expensive! Won't regular 1500-2000mi oil changes with 20w50 do the trick? My regular ride is a 900f (no comments from the peanut gallery, please) and I've already been topping off that bike with the Havoline 20w50. The clutch in that bike isn't so great to begin with so I'll probably never know if it's doing me any harm

As long as the Havoline does NOT have any "friction modifiers" I think you will be just fine.

RonKZ650 wrote:

I ran Castrol GTX for the entire 160,000+ miles on the KZ650. Last time I went to drain the oil it was all sludge and would not drain. The engine was clean up until the last few oil changes. I have question whether the formulation of the oil was changed where it was no longer usable in a motorcycle from this so I won't use it. Probably just a worn out engine, but the same idea as when you get the flu you always think of the last thing you ate as being what made you sick. This engine got real sick on Castrol.

Ron, you got 160,000 miles out of it...that's probably 5 times the amount a normal bike ever gave. I think your engine was worn out too, and I don't see how with that many miles it can be said Castrol did it. Don't you think Castrol probably got you that many miles?

I use Castrol GTX too, or sometimes Shell Rotella, or maybe a bit of convenience store oil if I'm on the road. I change it every 1,500 miles because I believe by that time the tranny has done it's best to break it down.

I hate to add to an oil thread but I have 12 quarts of Havoline 20w/50 and when my kz550 comes out of storage next week I intend to use it. Before storage I did an oil change with castrol gtx 10w40 and rode it just long enough to get the oil warm and the fuel stabilizer through the works.

I don't want to run the 10w40 for long but all these oil threads have me spooked. I'd like to run 4 cycle bike oil but it's expensive! Won't regular 1500-2000mi oil changes with 20w50 do the trick? My regular ride is a 900f (no comments from the peanut gallery, please) and I've already been topping off that bike with the Havoline 20w50. The clutch in that bike isn't so great to begin with so I'll probably never know if it's doing me any harm