Newbie here with an oil question...

[Ma-fia]

Hi, I'm new to this board, but I've read a few articles and broused through forums quite a bit. I find a lot of information very useful and interesting (this site is in very high regard at Ultimate Subaru board).

I would appreciate your opinions on differences in oil weights to use for older and newer engines. For the new Ford I have I'm using 5w20 (as recommended by manufacturer). Since I'm in Texas, I am inclined to use 10w30 or 0w30 in summmer.
I also have an older Subaru and it has 140+ miles on the engine. I am using 10w30 in it, and I am questioning if it's a proper weight for this engine. I have been doing some reading on oils and oil filters lately and trying to form some sort of opinion of my own.
Also, would a synthetic oil (like Mobil-1) be a good idea for an older car?
I tried to search, but the search didn't turn up any answers for me. Thank you for your help.

 

[Spector]

Until something changes such as increased oil consumption I see no reason to go to a higher viscosity oil jsut because the engine is older. I have been with my 10W30 since new and now 162,000. If it ain't broke don't look for a solution.

As to synthetic for an older car, I would vote no if all is operating fine as, IMO , you run a slight risk of oil seepages turning up.

Now, if I had a 5W20 recommended on a new car I would probably use the Mobil 1 0W20 which appears to be getting great results and/or the 0W30 as well.

 

[TooSlick]

The best way to evaluate viscosity requirements is to spend $20.00 and have the used oil tested after 5000 miles. Your lead wear should be much lower than your iron wear, particular for a large displacement, V-6 or V-8 engine....

If lead wear is > 1.5 ppm/1000 miles, I'd go up a grade in oil viscosity,say to a 5w-40 or 10w-40. High levels of both copper and tin is also a bad sign.

Oil pressure and oil consumption are two other things to look for. You need at least 10 psi/1000 rpms of engine speed to avoid excessive main/rod bearing wear....

Tooslick
Dixie Synthetics

 

[Ma-fia]

Thanks for the answers, for my '02 Ford Focus I've just got its first batch of 0w20 & a Wix filter. I can't wait to see how it works.
I've heard that synthetic oil has a tendency to leak more than regular, and it doesn't bother me much.

I have also heard that once you switch a car to synthetic oil, you don't want to go back to regular, because synto does something to the gaskets. Is that true?

 

[Al]

quote:

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Originally posted by Ma-fia:
Thanks for the answers, for my '02 Ford Focus I've just got its first batch of 0w20 & a Wix filter. I can't wait to see how it works.
I've heard that synthetic oil has a tendency to leak more than regular, and it doesn't bother me much.

I have also heard that once you switch a car to synthetic oil, you don't want to go back to regular, because synto does something to the gaskets. Is that true?

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You can switch back if you so desire. There is a slight possibility that an older vehicle may seep slightly but that's not at all certain. I have not had the problem and I have switched several vehicles with over 50K miles to synthetic.

 

[Ma-fia]

Actually, the older car (1982 Subaru) has much more than 50K -- 146+. And I was wondering if anybody had ideas on the best oil weight for it. The factory standard is 10w30, but back in '82 nobody had Mobil 1 0w40 (or 0w30) available. I never had anything synthetic in that car, and I'd like to know if it seems like a good idea. I am a very mild driver, not a racer and appreciate engine longevity much more than a few extra seconds gained along the way.
Appreciate the answer.
Ira