You have to remember that manufacturers' recommendations for weight are almost always about the "lowest common denominator" - how bad could it get. You might find a recommendation fo for 10W-30 above certain temps, simply because of higher oil volatility of conventional 5W-30 at the time. That doesn't take into account the lower volatility of synthetic 5W-30s.quote:
Originally posted by pscholte:
A 0W-30 synthetic exceeds the performance characteristics of a dino 5W-30 so I think an OEM would have a hard time trying to "getcha" because you used a synthetic 0W-30 where a dino 5W-30 was acceptable. I don't think they would even press it if you used GC in a Vette where 5W-30 synthetic is required.
There lies the rub. The dealership or carmaker isn't going to do any additional research. Suppose they do have their own research on the use of 0W-30 oils and find that it's suitable. If the owner's manual doesn't state that, it's an opening for the manufacturer to deny warranty claims. Now GM did recommend 0W-30 oils for extreme winter conditions at one time.quote:
Originally posted by Woody:
I've read where Mobil discontinued their 0W20 Mobil-1, which was supposed to work in 5W20 applications, due to dealers/manufacturers disallowing warranty claims. They replaced it with Mobil-1 5W20.
My Chevy Optra manuals says most of the same, but does not recommend going thicker than 5W30.quote:
gudmund Wrote:
quote from a 2000 GM Chev Metro owners manuel "If you are in an area where the temperature falls below -20F(-29C), consider using either an SAE 5w30 synthetic or an SAE 0w30 oil. Both will provide easier coil starting and better protection for your engine at extremely low tempertures." I have read this in other GM manuels also. Whats funny is that this quote was from a manuel for a Chev Metro but cannot be found in my manuel for my Suzuki Swift which is the same car. Both manuels do say 5w30 is the preferred oil but your can also use 10w30, they also say 'DO NOT USE 20W50'.
SE05,quote:
Originally posted by SE05:
Let me throw this out there.
I was under the belief that oils with narrower viscosity ranges were higher in quality than those with wider viscosity ranges due to the additives needed to make those wider ranges possible.
This might only apply to Dino, and not synthetic.
Anbybody else hear this?
And based on this, a 5-30 would be a better oil than a 0-30, due to the narrower range
0W viscosities fall within the definition of 5W, so either can be used. Perhaps Mobil only changed the labelling of their 0w20, renaming it to 5w20.quote:
Originally posted by Woody:
I've read where Mobil discontinued their 0W20 Mobil-1, which was supposed to work in 5W20 applications, due to dealers/manufacturers disallowing warranty claims. They replaced it with Mobil-1 5W20.
I think that is a very plausable assumption UNLESS Mobil is responding to OEM issues, in which case they might figure the OEM guys are watching the viscosity numbers to see if there is an actual change.quote:
Originally posted by oilyriser:
0W viscosities fall within the definition of 5W, so either can be used. Perhaps Mobil only changed the labelling of their 0w20, renaming it to 5w20.quote:
Originally posted by Woody:
I've read where Mobil discontinued their 0W20 Mobil-1, which was supposed to work in 5W20 applications, due to dealers/manufacturers disallowing warranty claims. They replaced it with Mobil-1 5W20.
That's what bothers me about the standard SAE viscosity classifications. They say little about actual suitability for the purpose. There are some indications that the SAE J-300 viscosity spec might be supplemented with a "triangle" that provides a detailed fuel economy rating, the HTHS, and low temperature limits,quote:
Originally posted by oilyriser:
0W viscosities fall within the definition of 5W, so either can be used. Perhaps Mobil only changed the labelling of their 0w20, renaming it to 5w20.quote:
Originally posted by Woody:
I've read where Mobil discontinued their 0W20 Mobil-1, which was supposed to work in 5W20 applications, due to dealers/manufacturers disallowing warranty claims. They replaced it with Mobil-1 5W20.