Motor oil Guru's, please help

[dirty slut]

Ok, so the previous owner has been putting in Mobil1 synthetic 10W 40 for the past two years. They do not have Mobil1 fully synthetic 10W 40 here anymore, and was told that they stopped carrying it, I went to all of the local parts store and was told the same thing. If I really wanted to im sure I could find it online but it would be expensive by the time it got to me. I was told by someone if it has had a 40 weight in it for so long I need to keep using it. What should I do, can I go to 10W 30 or will that be too thin (possibly causing gaskets to leak). The only 40 weight around here is 0W 40.

Its a 92 5.0 manual w/ 100K miles, located in Florida.

 

[HISSIN50]

M1 10-30 and M1 15W-50 are the normal steps (I dont know that I have seen 10-40 M1 for cars around in the past.

In any case, you can try running 10-30. If the gaskets and seals are in decent shape, which they should be considering a PAO based synthetic has been used, it should be fine. Or if it is pretty cold when you start the car, a 5W-30 might be a smarter choice.

Good luck.

 

[Roland69]

10-30 would work fine

 

[Michael Yount]

He's in FL -- the 10W will be fine for FL. Try the 10w-30 and watch the pressure gauge for changes. If it drops noticeably - you might try 15w-50. In FL it should work fine year round.

 

[powerpapa]

oil

Try this..http://motorcycleinfo.calsci.com/Oils1.html

 

[Grn92LX]

You have to get mobil 1 extended performance if you want 10W40. Regular mobil 1 does not come in 10W40. I use a mobil 1 extended performance filter too

 

[JUCD 5.0]

10-30 would work fine

I agree, thats what i run.

 

[86bluecobra]

i was running 5w50 in my car with no ill effects. kinda expensive but thats about it.

 

[dirty slut]

You have to get mobil 1 extended performance if you want 10W40. Regular mobil 1 does not come in 10W40. I use a mobil 1 extended performance filter too

they dont sell it here.....

Most people are saying they use 10W 30, which is cool w/ me, Id prefer to use that weight anyways. But I just didnt know if it is ok to run a 40weight for atleast 2 years, and then bump it down to a 30 weight

 

[sgarlic]

i was running 5w50 in my car with no ill effects.

What company makes 5w50? I've seen several threads referring to Mobil 1 making it, but don't see it on their site, nor have I ever seen anything lower than 15w50 in the stores. Hard to believe there's a spread like that available.

 

[HISSIN50]

I think Castrol makes a 5W-50.

 

[Michael Yount]

BMW makes a 10w-60 -- required for the M3...

 

[90lxfoxbody]

i've been using valvoline dura bland 10w40 since it came out and i change my oil at or before 3,000 miles religiously. even with 3,000 miles the oil is still very slick and looks relatively clean. i'm sure i could run it a bit longer but it's cheap insurance.