Unwise to use X-30 where 5w-20 is specified?

[TiredTrucker]

Originally Posted By: LEADED
Amazing , why are people hang up about API PCMO . Most API 5w 30 will shear dowm to a 20 weight oil in few K miles . I will take a STEADY 5W 20 over majority of API 5W 30 .Lower VII less shear, Lower Noack than a 30 weight. If 5W 20 was specified I will not lose sleep over it .


I suppose. I have been fond of 10w30 in many applications year round for a long, long time. In that grade as a full synthetic, it is likely to be basically a straight 30w that meets the cold flow of a 10w30. Shearing issues substantially reduced.

 

[Sealbilly]

Thanks guys. I will change my pcv valve and run 30 weight oil of some type.

 

[tig1]

I would say it is not unwise to use a 30wt oil in engines calling for a 20wt, with the possible exception of warranty issues. However my experience has been great using 20wt oils, in fact I chose to use 0-20 in my Ford engines because of the performance it gives.

 

[demarpaint]

Originally Posted By: Sealbilly
Is it unwise to use 5w or 10w30 in a car that calls for 5w20 if it has high mileage like 225k? Honda element 2003 is starting to use a little oil. I have always used synthetic and changed at 5k. My other vehicles call for 5w30.


I'd do it w/o hesitation. In fact I think it would help more than hurt in your situation.

 

[bunnspecial]

Once off warranty, all the FoMoCo engines I tend to get Mobil 1 5W-30 instead of the specced 5W-20.

I switched after becoming a convert to the "thicker is better" philosophy here

Some folks on the Lincoln LS Owners Club are racking up in the multiple hundred thousand miles without a rebuild running Mobil 1 0W-40. At the same time, there are other folks who have made it that far using 5W-20 or not even obsessing about the oil aside from changing it regularly.

Still, I have ZERO consumption with 5W-30 in the MKZ although it has 35K on it. Before the LS met an untimely death at the car in front of me, not due to mechanical issues, the oil consumption dropped noticeably after switching to 5W-30 although it wasn't bad on 5W-20. The engine was still running strong at 150K.

 

[Sealbilly]

Ok had the valves adjusted (They were way out) and pcv valve changed. I'm not ready for oil change yet but I topped it off with about 3/4 of a quart of valvoline maxlife 5w30. Next change I'll probably go with rotella T5 10w30 as I have several gallons.

We'll see...