Rotella T Engine Oil....

[gm7]

Hi Everybody,
Its been a while since I posted. My '01 SC2 5 spd has continued to run beautifully on Mobil 1...now with still only 48K on the clock...quiet and with great driveability. Have been considering changing to Rotella T which is what I run in my V twin motorcycle with good success. Those may know that Rotella T is approved for gas and diesel engines and is a Group III syn oil with great wear inhibitors. Please let me know if others have run Rotella T 5-40W with good success and curious what your oil consumption has been with it? Cost delta for 4 qts would only be $7-8 or so between Mobil 1 and Rotella T since only a 4 qt sump. My engine honestly only uses a modest amount of oil with Mobil 1 and I may be penny foolish to change.
Thanks for any experiences.
George

[97coupe]

Unless your engine is using oil I would advise against it. The 40 weight rating at higher temps will increase the power required to shear it and reduce MPG a bit and sometimes it can even increase oil consumption in a tight engine because it is harder to scrap the thicker film off of the walls of cylinder. If you want to use SYN oil in it, stay with 5w30 in summer unless you live in desert southwest where temps can get to 100 and beyond in summer.

[gm7]

Originally Posted by 97coupe

Unless your engine is using oil I would advise against it. The 40 weight rating at higher temps will increase the power required to shear it and reduce MPG a bit and sometimes it can even increase oil consumption in a tight engine because it is harder to scrap the thicker film off of the walls of cylinder. If you want to use SYN oil in it, stay with 5w30 in summer unless you live in desert southwest where temps can get to 100 and beyond in summer.

Sounds like good advice. Figured the extra 10 points in viscosity in warm weather maybe just noise but what you write makes sense. It runs so good on Mobil 1 I likely shouldn't switch. Price per quart becomes a bigger factor in large sump cars and bikes. My motorycle takes 6 qts for example...or half again that of the SC2...lol.
Thanks,
George

[97coupe]

Originally Posted by gm7

Sounds like good advice. Figured the extra 10 points in viscosity in warm weather maybe just noise but what you write makes sense. It runs so good on Mobil 1 I likely shouldn't switch. Price per quart becomes a bigger factor in large sump cars and bikes. My motorycle takes 6 qts for example...or half again that of the SC2...lol.
Thanks,
George

You know for what it is worth, I have been "testing" Walmart SYN oil in my wifes car for about 4 years now (not a Saturn) and it has worked out well but I still change it too regularly but it is about 14 bucks a 5 quart jug or about 1/2 the price of mobile one here. I am basically a conventional oil guy here but have run some extended tests on cars over last 25 years that where bought new and started on both kinds of oil after break in. I still maintain after all of this that frequent changes is more important that whether it is SYN or dino because I have yet to wear a engine out either way that I started new with. .

[gm7]

Originally Posted by 97coupe

You know for what it is worth, I have been "testing" Walmart SYN oil in my wifes car for about 4 years now (not a Saturn) and it has worked out well but I still change it too regularly but it is about 14 bucks a 5 quart jug or about 1/2 the price of mobile one here. I am basically a conventional oil guy here but have run some extended tests on cars over last 25 years that where bought new and started on both kinds of oil after break in. I still maintain after all of this that frequent changes is more important that whether it is SYN or dino because I have yet to wear a engine out either way that I started new with. .

Yup, another good point. The engine oils of today are very good across the board. You can take a Group III dino base oil which is marketed under a Synthetic name even though 90 percent mineral oil and it can be formulated more slippery then a PAO based Group IV bonefide Synthetic oil just by virtue of its additive package which at the end of the day trumps the base oil for wear and lubricity. The benefit of PAO based oils aside from anti-Newtonian temp viscosity relationship is resistance to viscosity/sheer breakdown over time. This only matters if you extend your oil changes which I do a bit in my Saturn. I run Mobil 1 and change it at 5K versus say 3K for a dino based oil. This improves the economy of scale of pricey PAO based oils like Mobil 1 versus conventional oil and keeps me from jacking the car up as much. A Saturn on a good dino oil will likely go 200-300K miles without taking the bottom end apart. I also run the slightly longer filter which fractionally increase sump capacity and may provide just a bit more storage for debris however not sure if it effectively filters better.
Thanks again for your experience,
George

[SlowSC2]

I thought it would be a 40w at lower temps?

[oseberg]

Originally Posted by 97coupe

I still maintain after all of this that frequent changes is more important that whether it is SYN or dino because I have yet to wear a engine out either way that I started new with. .

Have you ever actually worn an engine out by failing to change the oil? I've been through several handmedown vehicles that were given to me in very neglected condition, and I continued to neglect them. The only maintainance was repairs of failed parts, keeping the oil pressure light from comming on, and keeping them from overheating. And I have yet to wear out an engine by neglecting oil, and filter changes. I actually saw one vehicle when I was a kid with an oil pressure gauge that was reading fine when you'd start the car, then if you reved the engine, it would go up, then down to below where it was before you reved it. Then you rev it again and it would do the same but end up with even lower oil pressure. You could do this a few times and get the pressure really low, then stop the car, wait a few seconds, then restart it and the oil pressure would be high again. Changing the oil filter solved the problem. This was in an MGB with an oil filter so old that it was full of junk that would get stirred up and clog it more every time you reved the engine just like a fuel filter I once had.

That said, I still don't recommend doing this to a car you care about or really need to keep running, but pretty much the only important thing is to not run out of oil. As long as there's enough in there to keep the oil pressure within specs, the type of oil, amount of oil, and the age of the oil really doesn't matter much.

However, I haven't experimented enough with my Saturn to know if the type of oil has any effect on the clogging of the rings. I suspect that the additives are more important than the oil itself. You can probably be fine with using the cheapest oil available, and using some sort of engine flush product maybe every 5 oil changes or something.

Originally Posted by westwind999

Don't forget to check the rating on the oil. Some of the old straight weight oils are SB or something and WILL ruin your engine. Modern oils are SL or SM but you can still buy SB for antique engines.

Can someone explain what SB, SL, and SM are? And why would SB ruin an engine?

[97coupe]

Originally Posted by oseberg

Have you ever actually worn an engine out by failing to change the oil? I've been through several handmedown vehicles that were given to me in very neglected condition, and I continued to neglect them. The only maintainance was repairs of failed parts, keeping the oil pressure light from comming on, and keeping them from overheating. And I have yet to wear out an engine by neglecting oil, and filter changes. I actually saw one vehicle when I was a kid with an oil pressure gauge that was reading fine when you'd start the car, then if you reved the engine, it would go up, then down to below where it was before you reved it. Then you rev it again and it would do the same but end up with even lower oil pressure. You could do this a few times and get the pressure really low, then stop the car, wait a few seconds, then restart it and the oil pressure would be high again. Changing the oil filter solved the problem. This was in an MGB with an oil filter so old that it was full of junk that would get stirred up and clog it more every time you reved the engine just like a fuel filter I once had.

That said, I still don't recommend doing this to a car you care about or really need to keep running, but pretty much the only important thing is to not run out of oil. As long as there's enough in there to keep the oil pressure within specs, the type of oil, amount of oil, and the age of the oil really doesn't matter much.

However, I haven't experimented enough with my Saturn to know if the type of oil has any effect on the clogging of the rings. I suspect that the additives are more important than the oil itself. You can probably be fine with using the cheapest oil available, and using some sort of engine flush product maybe every 5 oil changes or something.

Over the years I have had a few used cars that I got real cheap that had received poor maintainance and they were oil burners and had poor oil pressure too and I have seen a few friends ruin engines from not changing oil.

Originally Posted by oseberg

Can someone explain what SB, SL, and SM are? And why would SB ruin an engine?

SA is basically pure motor oil with no additives. SB had some anti wear and anti oxidation additives but still no detergent. (SB is good break in oil on a fresh rebuild to run a few hundred miles) Starting with SC they added detergent to it and with each increasing grade they have added more to oil (detergent, anti foaming etc) Below is a link to a general chart of ratings.

Click here