[Guest]

my amc 360 is just rebuilt,but already has small leaks,i dont want to mak'em gushers with sythetics,but i want a good oil just the same.also if i understand correctly,a 10w40 will stay thicker even when hot than a 10w30,is that right?tia

jsjps

 

[dave]

I will not comment on which engine oil brand is better than another. I'd say the most important thing about engine oil is to change your engine oil on a regular schedule. My vehicles are very high in mileage,(one has over 200,000 miles) I use the major brand name of oil that is on sale when I'm buying oil. I've never felt that the discount store brand of engine oil would be of good quailty,(my personal opinion). You are correct about the 10W-40 being heavier than 10W-30. For a new rebuilt engine I'd use the 10W-30. A heavy oil will not flow well with an engine that has good close engine bearing clearances.
dave

 

[Guest]

The clean kind.

 

[Guest]

the thing to remember is to watch the little coin (for lack of a better word) on the back of the bottle. if you vehicle is more than two years old, than the rating on any oil today far exceeds what was required when it was new. all oil must go through SAE testing and recieve a classification before it can be sold (ie SE,SF,SG..... i think it is up to SJ and maybe beyond by now). the other thing to look for is energy conserving compliance. the better oils are ECII.

as has been said before, keep it clean, change it often.

dan
Good things come to those who do research!!

 

[Guest]

If you buy a brand name non-synthetic oil that has the highest SAE classification for a gasoline engine, that has the correct viscosity range for the ambient air temperatures where you live, and you use a good oil filter, and change the oil filter and the oil every 3 months or 3000miles, then you will get the maximum life out of your engine from a lubricating oil standpoint.

If you don't have access to an owners manual from a vehicle with your engine type which would have that neat little chart of oil viscosity versus expected ambient air temperature, then I think it would be safe to use 10W30 oil year round. Just change the oil and filter every 3 months or 3000 miles, whichever comes first.

For a general explanation of oil viscosity designation, the 10W30 means that the oil "behaves" like a thinner 10 weight oil at lower temperatures and it "behaves" like a thicker 30 weight oil at higher temperatures. So, basically, it can flow freely and easily to do its lubricating job throughout the temperature range that it's designed for.

The original owners manual for my 89 YJ with the 4.2L I6 calls for 10W30 for the temperature ranges expected in Virginia where I live. My 96 Chrysler Town & Country minivan with a 3.8L V6 calls for 5W30 for maximum fuel efficiency.

For oil filters, I use Purolator Pure One exclusively.