What Oil weight to use?

[Morales]

My car has roughly 100K Miles on it.. i've only had it 3 months and im getting ready for it's second oil change while under my owner ship. What oil weight should I use? Should I go for synthetic or not? I used a high weight synthetic last time.. can't remember what it was. thanks and sorry for the newb question

 

[srothfuss]

Oil weight is really up to you. If you ran synthetic last time and you didn't develop any leaks than you should be OK with it again. My personal preference for oil weight is 10w30 in the spring and 10w40 in the summer to help with oil pressures but still keep the oil thin

It's all up to you.

 

[sunil6784]

Yup. 10W30/10W40 is what most people do i think. Its a good all around weight.

 

[The Shape]

I use 10W40 winter 20W-50 summer

 

[MrKwik]

I WOULD NOT go synthetic on a high mileage engine. I speak from experience.

 

[Realmongo]

I go with Ford's reccommendation of the 10W-30 for my driving. The reason you should stay away from the synthetics on a high milage engine is if there is a worn seal to be found, the synthetic will find it and promptly depart your engine on a regular basis.

 

[srothfuss]

I go with Ford's reccommendation of the 10W-30 for my driving. The reason you should stay away from the synthetics on a high milage engine is if there is a worn seal to be found, the synthetic will find it and promptly depart your engine on a regular basis.

I agee with that statement, but he said that he previously ran synthetic without any issues. I guess it would really depend on how black (dark) his oil was when he changes it. If it is really dark or dirty maybe there won't be any sludge to stop his motor from leaking. Or maybe his oil was still clean when he changed it and it didn't / won't leak. Only way to find out is to try it

 

[50gt1988]

I agree with the claim of synthetic oil finding an escape in older engines but I have 190,000 miles on my 1988 5.0 and I run synthetic oil. The car still runs very strong and clean with little oil burnoff. When I switched to synthetic I added a bottle of Lucas Oil Treatment with the synthetic. I have better oil pressure and hardly any oil burnoff. Now I use Lucas in everything I own.

 

[BlownStangGT]

I put 10w30 in which is what i always ran, I read the factory manual and thats what it said to run

 

[DW5.0L]

I use 20W50 and just rebuilt the engine at 197K. The manual says to use either 10W30 or 10W40 depending on temperature.

 

[2badazzstangs]

i use mobil 1 5w 30

 

[Carbed86GT]

Everything you want to know about motor oil.
http://www.boss302.com/oil.htm

 

[HISSIN50]

One generally wants to use the least viscous oil which provides sufficient pressure in all operating conditions. If 10W-30 does not cut it, step up.

James and I run the same oil weights, winter and summer. I am not gonna run 10-30 in 111*F temps. No thanks.

 

[sgarlic]

I'd run 10w40 Synthetic. If you develop a leak, then it's time to replace the gakset. Sorry, it's a fact of life, you're going to have to replace stuff on older vehicles. Might as well replace instead of putting a band-aid on it (a quote from Hissin.)

 

[The Shape]

I did run 15W-50 synthetic mobile1 last summer. It might have made my rear main leak a bit worse , but it stopped when I switched back to regular dino oil. I have nothing against synthetic. If I were to build a new engine or get a new car I am sure synthetic is all I would run. I just feel like since this car has made it to 120K now with no problems on dino oil I will just stick with it, so I decided to use th e20W-50 GTX this summer instead of the synthetic Mobile 1 15W-50.

 

[89MustangGX]

One generally wants to use the least viscous oil which provides sufficient pressure in all operating conditions. If 10W-30 does not cut it, step up.

I'll agree with that. I'm not a big fan of heavy oil at all unless you absolutely need it.

 

[ECU5.0]

I'd run 10w40 Synthetic. If you develop a leak, then it's time to replace the gakset. Sorry, it's a fact of life, you're going to have to replace stuff on older vehicles. Might as well replace instead of putting a band-aid on it (a quote from Hissin.)

right on with that statement. synthetic oil doesnt cause leaks, it just makes leaks that were previously there more apparent because of their cleaning abilities and the fact that they have a lower pour point that conventional oil. if you want the straight dope on oil check out www.bobistheoilguy.com , i used to run lucas oil stabilizer in my car (and i liked the results) until i saw a test done by someone on BITOG. oil is a very touchy subject with a lot of people because they think that high mileage engines shouldnt use anything but very high weight oil. i know people that own mechanical shops and all they buy is 20w50 and they put it in everything from toyotas to cadillacs. ive seen guys pour 20w50 into 2003 escalades that had maybe 20k miles on them. they reasoning behind this they say is that "it is hot outside and it helps." my car has 208k miles on it and i run 10w40 and have perfect oil pressure and hardly burn any oil. as far as the first post goes, keep running synthetic if you didnt have any oil pressure problems and just stick with 10w30. thats all i have to say about that

 

[HighMileage]

Just depends on where you live. 10-30 for normal temperatures.

 

[Morales]

Im in Miami! It's hot and Humid.. im going to try 10w30 and see how it goes..

 

[The Shape]

See Miami is a climate I would think the heavier oil would be a good idea in.