Recommended Oil Wt. for M6 and 635?

[ben7]

What are the recommended oil wts. for M6 and 635? Is the weight of oil the same for both vehs or different?

[samsonevickis]

I can't vouch for the M6 folks.

But the M30 engine does best with 15W-40 Shell Rotella or the Chevron variety in the Blue bottle. Both have trucks on them, but they are preferred.

I know my local dealer uses Castrol 20W-50, but some here and I agree think it's a little to thick.

[scottswash96]

10/40,15/50,15/40 is fine....more importantly is change your oil on a regular basis.I personally use 15/40 rotella or 10/40 castrol gtx in my m635csi.

[oxen]

i run 15-40 year round. mobile delvac 1300 super.

[Alex E24 E30]

I always go with the owner manual specs, which I think is 15W-40.. Honestly, I can never remember what weight I put in mine, but I always go with full synthetic Mobil 1. But as mentioned earlier, regular oil changes do more for and older engine than anything. Keeps things clean, and the synthetic helps, too.


Alex

[av8r4aa]

Castrol 20w/50
Year around. Both 635 and M6.
Because it is soo damn hot here.

[chevale]

I'll add Valvoline VR1 racing Oil 20W-50 to the list.

[team2win]

my manual says for my 84' 633 to use 20/50
when checking computer at autozone, it says use 15/40...

[Gunz635]

I use Mobil1 extended milage. 10w30 is enough for me. have been using it for 10 years. I recently did a head gasket job and found the pistons walls in great condition and my camshaft not worn at all. So i guess its doing the job for me.

[oldymcoldington]

i don't know know why you would take autozone's word over the manuals...

[Steve M6]

Valvoline 20W-50 in my 635CSi

Valvoline 20W-50 (20@-50) Racing Oil in my M6 (because of additives and the $ to maintain)

I don't abuse either car. Old school 2-3000 mile change intervals too.

[ben7]

Great information from all you guys. :thumbup:

[vickumar]

Using Valvoline VR1 Racing Dino 20W50 (High Zinc)

[CW6er]

1) Engine Oil:
I would be careful about going to a lighter (5w30/10w30) oil in the M30.
My owners manual for my 1987 635csi has a diagram in which it shows the temperature range acceptable for various grades of oil as follows:

Weight .............Temp Range
20w50 = aprox. 14 F to 122 F .... or -10 C to 50 C
15w50 = aprox. -4 F to 104 F .... or -20 C to 40 C
15w40 = aprox. -4 F to 86 F ...... or -20 C to 30 C
10w50 = aprox. -22 F to 68 F .... or -30 C to 20 C
10w40 = aprox. -22 F to 50 F .... or -30 C to10 C
10w30 = aprox. -22 F to 40 F .... or -30 C to 4 C
. 5w30 = aprox. -40 F to 23 F .... or -40 C to-5 C
. 5w20 = aprox. -40 F to 14 F .... or -40 C to -10 C

Special Oils * -40 F to 86 F or -40 C to30 C
(* Special Oils formulated and approved by BMW (Read Synthetic). See BMW stealer....opps! I mean Dealer.. for Info.)
It also lists straight weight oils as follows:
SAE 20 from -4 F to 50 F or -20 C to10 C
SAE 30 from 32 F to 86 F or 0 C to 30 C
SAE 40 from 68 F to 122 F or 20 C to 50 C


As you can see the common 10w30 is only good up to 40 deg. F.

In the past I used Castrol RXsuper 15w50 (it was a diesel oil). It protected from -4 F to 104 F and was perfect for year round; so naturally it disapeared from the shelves a couple of years ago. So I switched to Castrol 20w50 for awhile and now I'm going to try the Chevron Delco 400 15-40.

[LarryM]

For the nearly 15 years I've owned my 635 I've run 20W-50 Redline (synthetic). However, it's always been a third or fourth car and is only driven in fair weather, a max of about 1500 miles/year. In this car I'm running synthetic oil more to avoid sludge buildup rather than for optimal oil performance or longevity. I usually wind up doing an oil change ~every 18 months.

You could probably pick up some measurable HP by running a lower weight oil such as 10W-30 or 10W-40, but as previously mentioned an xxW-50 weight is what's specified in the owners manual for offering the most year-round protection in all but cold climates.

[Badgas]

I live in a mild and occasionally damn hot area and my m635 is a daily (but short distance) driver.

I run Castroll 20-50 high milage. Oil change every 3000 miles

[88M6]

i run Valvoline Racing oil 20/50 in both M6 & B7 Alpina turbo engines

[Zack01GC]

I've run both 15W-50 and 20W-50. Always synthetic. Always Mobil1 or Castrol.

[team2win]

i don't know know why you would take autozone's word over the manuals...
I thought it was interesting that the manual says 20/50 but there are a lot who use 15/40.. but as eluded to, it may also depend on the temp in your area most of the year..

[wjtesquire]

Frank Fahey recommended Brad Penn 20-50 for my M635

[Bert Poliakoff]

Frank Fahey recommended Brad Penn 20-50 for my M635

+1. High zinc concentrate,which is good for an overhead cam, but I think Shell Rotella hs the same.

[joecoolinatl]

I've usually used 20-50 in the 633. this time I had a local shop do the oil since I was short on time, didn't realize till after they put 5-30 (Valvoline) in it tho. engine has actually seemed to run cooler since.

[CW6er]

5 weight oil is just too low for these old engines, they weren't designed for it (5wt didn't exist when the engine was being built). That is an oil for modern engines designed for it.

[SharkInfested]

I almost had a panic attack buying oil for my M6 today. I've had a 635 for years, but acquired an M6 this summer and want to change the oil this weekend. The manual read "15w40 or 50" for M6. The only oil I found in these grades was a diesel oil. I walked away dejected as "diesel" just didn't sound right to use.

Also, is there any truth that switching from conventional to synthetic oil may cause leaks to begin as the synthetic molecule is smaller than conventional allowing the smaller one to permeate through the gaskets used to conventional oil?

[joecoolinatl]

One of my buds was trying to convince me to run that weight today when I went to buy oil as he runs it in both of his f-350s.

[SharkInfested]

I'm guessing he didn't convince you.

[jeffcfp1]

+1. High zinc concentrate,which is good for an overhead cam, but I think Shell Rotella hs the same.

Bert, first time I've heard that Shell Rotella has the needed high zinc content.


What are the recommended oil wts. for M6 and 635? Is the weight of oil the same for both vehs or different?

Unless you are dealing with extreme ranges of temperature, it's not oil weight that matters, (and if you are go in the middle), particularly with a more aggressive cam such as the M88, i.e. versus the S38, it's zinc content, which for the newbies, has decreased dramatically over the years and as such isn't overly suited for solid lifter overhead cam motors.

Valvaline VR racing (only available in 20-50 or straight 50), Brad Penn, and supposedly Royal Purple (they don't publish their specs) are appropriate oils. There is a ton of documentation on such, particularly if you work the bobtheoilguy (http://www.bobtheoilguy) site.

I've read hours of research with quotes and comments from porsche engine builders, cam manufacturers and racing outfits and I'd stick with above.

I personally alternate between Valvoline and Brad Penn. A quart of Shell Rotella diesel when toping off between oil changes always has my 27 year master tech buddy giving me the "Wow!" when he notices the inside of the filter housing looking as clean and shiny as I keep the outside! :redspot

[Taylor Marshall]

After 9 years of using Mobil 1 I finally abandoned it last week and ordered 7 liters of Valvoline VR-1 Racing Synthetic in the 20W50 weight for use in my upcoming oil change. Mobil and Rotella have progressively decreased the ZDDP additive levels in their motor oils to the point where they are just not acceptable to me and, as Jeff pointed out in his above post that I 100% agree with, there is a very short list of oils now still available with a +1300 ppm ZDDP content.
In these parts at least Napa seems to have a lock on the VR-1 distribution but even their own retail outlets do not stock it (which might be a seasonal inventory choice as 20W50 is not going to sell real well in the depths of a Canadian winter) and I had to get my techie to order it direct from their regional distribution warehouse which only had a grand total of 12 liters in stock !

As for the potential issue of switching from dino to synth causing oil leaks I guess it must happen from time to time as everyone has heard of it but it's rare to find someone that it actually happened to and that a simple tightening up of , for example, the oil pan connectors, could not fix. Conventional wisdom has it that synth can dissolve built up crud on gaskets more thoroughly than dino does and this results post switch in these gaskets getting leaky where the crud was washed away. There was no such problem in my car when the PO did the switch some 11 years ago and most folks have the same positive experience.
Anyway for those that want to stick with or revert back to dino then Valvoline also offers a high ZDDP racing dino oil in 20W50 that I imagine is also cheaper than the synth. See links for both options below.

I'm sticking with synth as I have to modify each new oil filter to accomodate a custom oil temp sender I installed in the oil filter cannister cap (see pic) which is a minor PITA to do so I want the extra longevity of synth over dino

http://www.valvoline.com/products/brands/racing/racing-motor-oil/8

http://www.valvoline.com/products/brands/racing/racing-motor-oil/6

[arctic745]

Redline 10-40, 15-50, 20-50 depending on temp on M engines also work well -- Redlines lean towards the high side of viscosity and recommend staying as low as possible with conditions. They are also high ZDDP in all their formulations. Redline also makes a ZDDP additive (break-in additive) that can be added to any other oil. Sounds like the specialty and race oils are the only ones with sufficient ZDDP.

[sofiabghome]

Hi,

No one hear used 10W-60 TWS ot 10W-60 Lubro Mouly.?!

I use on my daily driver 88 M6 10W-60 TWS Castrol but later switched to Lubro Mouly, no complains.

Oil consumption is from my original oil pan gasket .. 3000 miles oil change.

10W-60 oil grade is the best because you get both world hi temp revving engines and morning cold start.

I used one time 20W-50 but I can feel the engine, its thick oil.

I do track days and soon will sent the oil lap for analyzed..

Best
Anri

[jeffcfp1]

I have also read, I believe on the amsoil website, that synthetic in the U.S. isn't really synthetic, just a bunch of modifiers that strengthen the film type strength and hence durability of the oil.

Also, FWIW, it is my understanding that pennsylvania crude has more natural parafins(sp) and waxes than the crap that we import. Additionally, its refining process is minimal versus the crap we by from the middle east and elsewhere. I do business with an energy company (i.e. well driller and refiner) in western PA and as such have had the opportunity to pick one of their engineer's brains on these matters. What's great is that he's incredibly more objective than what the enthusiest gets from the major companies competing with each other. On a final note, Brad Penn 20/50 pours very, very slowly, stuff is like molasses out of the bottle, which perhaps explains why I've seen claims it's fractionally increased times against all other oils.

A bit more info on the subject...
http://motorcycleinfo.calsci.com/Oils1.html

[joecoolinatl]

I almost had a panic attack buying oil for my M6 today. I've had a 635 for years, but acquired an M6 this summer and want to change the oil this weekend. The manual read "15w40 or 50" for M6. The only oil I found in these grades was a diesel oil. I walked away dejected as "diesel" just didn't sound right to use.


I am thinking about switching from my normal 20-50 to 15-40
Most of the oils i've seen in that weight are usually used for diesels, all my friends with f250/350s / excursions run it. I may try it in the 633 this weekend.

[Coupenut]

Interesting, I just had this conversation about oil weights and conventional vs synthetic oil with my local shop when I took the 745i in for an oil change today. We decided on a conventional 15-40.

[joecoolinatl]

yeah think i may try the 15-40 this weekend in the 633. i'll probably get
shell rotella T-
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Rotella&174;-T-15W-40-Shell_8020590-P_N3259_T%7CGRP2046_____

or

Valvoline premium blue heavy duty
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Premium-Blue-Heavy-Duty-Oil-15W-40-Gallon-Valvoline_12017303-P_N3259_T%7CGRP2046_____

i'll let ya'll know which one / how it does

[gt40mk2]

I'm trying 20w40 as it is recommended in the manual for the temp range I want (0-30 celsius).

The ones you see in Canadian Tire all say "Diesel Oil" - I'm thinking because newer cars don't use anything that heavy so they say it's for diesels. I got Rotella.

Now I'm wondering about 20w40 synthetic and I see Castrol has one. Any others?

[GarmaZabi]

I run Synthetic 20W-50 in mine. can't go wrong with the manual.

[gt40mk2]

I run Synthetic 20W-50 in mine. can't go wrong with the manual.

What brand? Just curious 'coz there don't seem to be many heavy synthetics . . .

[chevale]

I'm trying 20w40 as it is recommended in the manual for the temp range I want (0-30 celsius).

The ones you see in Canadian Tire all say "Diesel Oil" - I'm thinking because newer cars don't use anything that heavy so they say it's for diesels. I got Rotella.

Now I'm wondering about 20w40 synthetic and I see Castrol has one. Any others?

Shell Rotella in Canadian Walmart on regular price is cheaper than in Canadian Tire in sale.