Valvoline SynPower 5W30 or MaxLife 10W40 for Thailand

[mipa]

there are about 100 discussions about motor oil and I've probably read about half of them today.. without finding "the final answer"

I live in Thailand and have basically this two options

Valvoline SynPower 5W30 which I've been using for the past years without noticing any issues, but a online shop (and chatgpt) recommended today the MaxLife 10W40 since it would be more suitable for hotter climates and older engines. There are also a bunch of conflicting posts claiming the 4.0 engine needs zinc and fully synthetic oils wouldn't have that.

Since I've about 42.000 miles on my engine, I wouldn't consider that high mileage... but my rubber gaskets definitely getting old - and I've replaced a bunch already. I probably drive a maximum of 50 miles per month.. I also had my RMS replaced about 5 years ago.. no leaks.

Any reason to switch from my 5W30 to something else? There is no 10W30 available here for some reason, so the next best would be the MaxLife 10W40

I saw older posts from @Kon and @TJim using the MaxLife

 

[TheBoogieman]

I'd just leave it alone and use what you've always used.

 

[mipa]

just checked underneath again today, before ordering and noticed that while I don't have drips on the ground around my oil pan and underneath is quite "wet".. I wonder if that MaxLife 10w40 with that higher viscosity would help with that... or if that's "normal".

 

[TheBoogieman]

just checked underneath again today, before ordering and noticed that while I don't have drips on the ground around my oil pan and underneath is quite "wet".. I wonder if that MaxLife 10w40 with that higher viscosity would help with that... or if that's "normal".

I'd clean it off and see if it's actually still leaking. I only use conventional high mileage oil in my Jeeps, regardless of the mileage on them.

 

[Gilaguy23]

If you were to look on one of the many oil websites and look up product sheets you'll see the high mileage oils have more ZDDP than the regular oils. They also have some sort of seal conditioner which is basically something that causes the seals to soften a tad and swell them up as well. I'll add that many years ago reading some oil posts a guy from South America sent a pic of his fairly new Cherokee with the 4.0 engine and on the oil fill cap it stated 15/40 was the recommended weight, not the typically seen 5/30 you'll see on USA versions. All the commercial 15/40 oils have typically very high ZDDP and high detergents as they are typically Diesel engine oils. Now in the US were seeing XX/30 wts for newer diesels likely for emission issues and Gov pressure for better fuel economy. The new gas engines here call for 0/20 or 5/20 oils anymore as well. I ran 15/40 in my 96 XJ 4.0 engine, but when winter hit and it was in the teens temp wise it was not a good thing. If I was in your shoes Id have no problem what so ever running xx/40, high mileage in my jeep. That is just my $.02 worth and you'll get plenty of opinions here.

 

[MountaineerTom]

The Max Life 10W-40will have plenty of zinc. I've been running Max Life 10W-30 since I got the jeep in 2016. No idea what the previous owner was using. I think they maintained it well though. I've done several Blackstone Labs Oil Analysis reports, and they have all been good with good numbers for zinc.