Reason for 5w20

[willy65000]

I'm brand new to this forum to please excuse me for what may seem like a stupid question but are Mazda and Honda recomending a 5W20 because it increases fuel economy or because there build tolerances are tighter now? I guess I just feel more comfortable using the same Castrol 5w30 in my new Mazda 2.3 that I used in my 94 Civic that I sold with almost 170K on the clock.


Bill

 

[Jelly]

quote:

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Originally posted by willy65000:
I'm brand new to this forum to please excuse me for what may seem like a stupid question but are Mazda and Honda recomending a 5W20 because it increases fuel economy or because there build tolerances are tighter now? I guess I just feel more comfortable using the same Castrol 5w30 in my new Mazda 2.3 that I used in my 94 Civic that I sold with almost 170K on the clock. Bill

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You mean clearances?

Yes, the reason behind 5w-20 is fuel economy (and fuel economy alone), but Ford was smart when doing this by designing a specification that required the oil companies to design a pretty darn good oil if these wanted to receive the Ford approval.

Because of this, any 'ol mineral 5w-20 on the shelf is guaranteed to be better than the same companies low-cost mineral PCMO 5w-30.

BTW, I used to be a die hard higher viscosity and high HT/HS type of guy. Time (and analysis) has shown though that these oils are keeping metal wear rates very low in the engines they have been suggested for.

For your new Mazda, I'd recommend going over to Wally-World and picking up some M1 0w-20.