Thicker Vs. Thinner Oil - BMW X5

[chefwong]

The recommended oil weight for my car is 5W30.
I plan to keep this car for a longtime and won't be sellling it before 150K miles.

I did a oil change at 3K miles with Redline 5W30.
Planning to do another one before winter. I'm located in NYC so I do get my fair share of cold weather.

If I don't really care about fuel consumption, by switching to a heaver oil like 10W30, will it be better for the engine ?

 

[Mobil2]

With it getting colder out now, I'd say your best off and probably safest to stick with the 5w-30.

 

[Al]

There are many opinions here. The 10W-30 oil is more shear stable in general than a 5W-30 oil. Hopefully someone will have some experience with the Redline 5W-30. It would be helpful if you did an oil analysis to determine if the 5W-30 Redline holds up. If not than you can consider an alternative grade or brand. The other issue is that if you are in the Lake Placid part of N.Y. and are getting temps consistantly lower than say -10F you'll really need to strongly consider the 5W vs 10W.

Hopefully you'll get better answers. I just happened to be sitting here

 

[pscholte]

You should be in good shape with either Redline or Amsoil 5W30, GC 0W30 or Amsoil 0W30. Since you want to keep the car awhile, I think your best bet is to try each one for three (at least two) shorter intervals, doing UOAs, find the one that your motor likes, and then stick with it. Of course, if you find that after any test, you probably can't improve by trying the next oil in line, then stop there and make that your oil.

[ October 01, 2003, 01:49 PM: Message edited by: pscholte ]

 

[Dr. T]

The BMW 5-30 Synthetic is good oil. However, in my experience it cannot go the full 10k mi. interval without causing severe sludge buildup over time. So, if you wish to keep your BMW until at least 150k, you need to either increase the oil change interval...probably adding an extra oil change over what's recommended....or increase viscosity...eg. a 40 or 50 weight....10-30 over 5-30 won't make a difference.

 

[vvk]

What you really should be looking for is BMW Long Life approval, no matter what weight. Any oil that has that approval will work exceptionally well.

 

[Mobil2]

I thought 0w oil provided the best cold weather starting protection. How would a 5w oil be better?

 

[williar]

I'll weigh in here and say the best weight would be either the OEM-recommended 5w30 or the 0w30. The important thing is that the oil meets BMW specs, ACEA A3 or whatever. A 0w40 might work well also. I'd stay away from the 10wX, or heavier, as that isn't what BMW recommendes.

You also can increase your oil change intervals to 10K miles, with a good oil such as Mobil1, Redline, or Amsoil. Do an oil analysis to be sure.

BTW, I'd say a 0wX is best for any-weather startup, not just winter, other things being equal.

 

[F1Crazy]

What engine you have in that X5? Sixes do well on 30wt oils but V8s respond better to heavier oils.

10W-30 is not really heavier oil than factory recommended 5W-30. Keep in mind that BMWs with the same 6 and 8 cylinder engines come with 0W-40 as factory fill in Europe. 40wt is to ensure good performance during prolonged high speed driving and 0W to deal with cold winter conditions, something I doubt you will encounter in NYC.

Red Line 10W-40 is the oil of choice for many BMW enthusiasts and is a great oil for both street and track use. I don't think your X5 will ever see a race track so your choice of 5W-30 looks like a good one.

 

[mikemc]

"If I don't really care about fuel consumption, by switching to a heaver oil like 10W30, will it be better for the engine ?" Not always. December and January in New York bring some pretty cold temps and the 5w30 will generally flow quicker at cold start then a similar oil in 10w30, in theory reducing engine wear. I would stick to a BMW approved 5w30, at least in cold weather.

 

[vettenuts]

quote:

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Originally posted by mikemc:
"If I don't really care about fuel consumption, by switching to a heaver oil like 10W30, will it be better for the engine ?" Not always. December and January in New York bring some pretty cold temps and the 5w30 will generally flow quicker at cold start then a similar oil in 10w30, in theory reducing engine wear. I would stick to a BMW approved 5w30, at least in cold weather.

---

I would be careful here if you want to keep your warranty in effect. I just bought a 325i and took a bottle of Amsoil to my dealer to get their approval. On the back, it does state ACEA A3 and BMW specifications. Not sure if Redline does the same. I am going to change out the factory oil at 3K and with Amsoil and also take Amsoil to the dealer for their required 15K or one year change out as well. This way I am not switching oils all the time.

I would stick with the 5W-30 and not even consider 10W-30. If I were to look at another oil, the first number would be a 0 rather then a 10 especially in the winter.

I am running Amsoil 5W-30 in my Corvette as well with excellent results so far.

 

[F1Crazy]

quote:

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Originally posted by TooSlick:
Redline formulates their xw-30's towards the upper end of the 30wt range, so it's significantly thicker than the Mobil 1, 5w-30/10w-30.

At the very least, you want to use something that is thick enough to meet the ACEA "A3/B4" specifications.

---

I don't have access to data on RL 5W-30 other than their website and it seems like it isn't much thicker at 100C (10.6 cSt) than M1 5W-30 (10 cSt).
What is the HTHS?

 

[TooSlick]

It's 3.8 Centipoise for both the 5w-30 and 10w-30, due to the thicker basestocks they are using. The drawback is somewhat poorer low temp flow properties, compared to Amsoil or Mobil 1.

Ted

 

[Patman]

Redline is another company who lists their viscosity lower than reality. Even though their data sheet might say 10.6, we've found on here that it's closer to 11.5.

 

[TooSlick]

I'd run the Amsoil 0w-30, or Series 3000, 5w-30 in any new BMW except their M3 models, so I think you are just fine with the Redline 5w-30. Redline formulates their xw-30's towards the upper end of the 30wt range, so it's significantly thicker than the Mobil 1, 5w-30/10w-30.

At the very least, you want to use something that is thick enough to meet the ACEA "A3/B4" specifications.

Tooslick
Dixie Synthetics