Is there any proof that higher viscosities (M1 15W-50) cause more wear in an engine ?

[Alex D]

I am specifically thinking about M1 15W-50 here. It seems to me that this oil could be an excellent choice in hot climates for summer driving and towin, especially in GM V8 pushrod engines (LT, LS). I do understand that you probably want to run it only in summers and not winters. I have seen of no evidence that anyone here using the heavier viscosity has had increased wear as a result. What in your opinion are the drawbacks of let's say 15W-50 compared to 10W-30 or 5W-30? It seems that M1 15W-50 has helped a number of people here to quiten down their mechanically noisy engines without causing any increased wear. Opinions/experiences please??!!

 

[ToyotaNSaturn]

I would think exactly the opposite---that higher viscosities reduce engine wear. Of course, again, not in cold weather.

 

[buster]

Alex, I think a lot of people run the M1 15w-50 when racing. In a LS1, it would be fine, but it might rob you of some HP. In the summer months mixing the 15w-50 with some 10w-30 is a great choice. I'd personally go with a 10w-40 in a LS1 if I had one. I'd probably use RL now that you can buy it at Advance Auto. The 15w-50 would be fine though and not increase wear. It has a more robust additive package then the other grades of M1, mainly being ZDP. In fact, I was reading somewhere that a guy with a Dodge Viper would run Mobil 1 15w-50 during the summer months and 10w-30 during the winter. [ April 03, 2004, 07:14 PM: Message edited by: buster ]

 

[Ryan00TJ]

I'm curious myself and will be running Schaeffer's 15W-40 Blend in my Cammed 399rwhp LS1 this summer to see what the wear numbers look like compared to my last 3 UOA's on Schaeffers 10W-30 Blend.

 

[Patman]

I for one would like to see more reports with 15w50 Mobil 1, and with 5w50 Syntec. I do think that we'd see better results in most engines with the 30 and 40wts though. And the newest Honda, Ford and Mazda stuff is doing very well on the 20wt stuff!

 

[Last_Z]

quote:

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Originally posted by Alex D: I am specifically thinking about M1 15W-50 here. It seems to me that this oil could be an excellent choice in hot climates for summer driving and towin, especially in GM V8 pushrod engines (LT, LS). I do understand that you probably want to run it only in summers and not winters. I have seen of no evidence that anyone here using the heavier viscosity has had increased wear as a result. What in your opinion are the drawbacks of let's say 15W-50 compared to 10W-30 or 5W-30? It seems that M1 15W-50 has helped a number of people here to quiten down their mechanically noisy engines without causing any increased wear. Opinions/experiences please??!!

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In response to your subject question.....We'll find out in a few months! I'm running 15W-50 in my LS1 with a brew of my own! I might even dyno the car and see if it lost HP. Stand by!