5-30 synthetic ok instead of 5-20

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May 29, 2005
Ozark Mountains
I know this has been covered a ton and 5-20 is safe but I would really like to use 5-30 synthetic instead of 5-20 that is called for in my 06 Hemi Dodge Ram 1/2 ton and a Mazda MX-5 convertible. No warranty left on either. I guess I just like using the 5-20. I would like to know if the 5-30 is safe. What do you think?
As long as the RAM doesn't have the MDS system then you can use the 5w30 and it will be just fine. The Mazda is fine IMO! Using anything other than a 20wt with the MDS system will cause it not to function properly and could result in damage!
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Yes. It will not hurt anything. Many people here run 50w oils in their vehicles and have had no issues.
IF the Ram has MDS, as others have said, use 5W-20 for proper operation! If either vehicle is still under warranty, use what is called for by the manufacturer! This is not complicated!
If you are going to use anything other than 5w-20, make shure it's a good product. Synth is overkill and frankly, not needed to blend a 30 weight oil. 0w-40, 5w-40, yeah...it takes a synth basestock for that, not 5w or 10w-30. I'm using Havoline Synth 10w-30 in my new Honda because I have it sitting here in-stash.
When cold, synthetic 5w30 pours exactly like conv. 5w20. When hot, the viscosity is slightly heavier 10.5 instead of 8.5, which to an engine is negligible. However the 10.5 will have better film strength. I would be perfectly happy running 5w30 synth, or 50:50 5w20 conv. with 5w30 synth. if u have MDS.
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