synthetic oil vs semi-synthetic - BMW M5 Forum and M6 Forums
E34 M5 Discussion 1988-1995 Sedan and Touring

 31Likes
Reply
 
LinkBack Thread Tools Rating: Thread Rating: 2 votes, 5.00 average. Display Modes
post #1 of 332 Old 20th April 2008, 06:49 PM Thread Starter
derhammer
Member
 
derhammer's Avatar
 
Join Date: Aug 2006
Location: Canada
Posts: 44
Thanks: 1
Thanked 1 Time in 1 Post
synthetic oil vs semi-synthetic

Hi,

I am a bit concerned, I went to a independant bmw specialist and he did my oil change with semi-syntetic motul 15w50 oil. I always used castrol tws 10w60 in my engine.

He told me the tws I was using, was useless in my engine because it was designed for the latests bmw m power engines. He told me the motul oil was better suited for my car and that i was paying to much for the castrol tws. My concern is the change from synthetic to semi synthetic... Am I doing something wrong?

Last edited by derhammer; 20th April 2008 at 06:56 PM.
derhammer is offline  
Sponsored Links
Advertisement
 
post #2 of 332 Old 20th April 2008, 07:11 PM
AfricaOffroad
Senior Member (>500)
 
AfricaOffroad's Avatar
 
Join Date: Sep 2007
Location: South Africa
Posts: 526
Thanks: 85
Thanked 76 Times in 37 Posts
A semi synthetic has a small percentage of Group 3 base oil in it - 10-20% IIRC.

Full synthetics comprise 100% Group 3 or Group 4 base oil. TWS is formulated with Group 4 (PAO).

TWS cannot even be compared to a Motul Semi Synthetic, the former is way way better in its lubrication properties. By way of example, normal group 1 base oil costs $1300per Ton. A group 3 costs about $2300per ton and a group 4 about $ 3500per ton. If oil companies could get the same lubrication properties with group 1s, believe me we would .

You dealer obviously has the Motul in stock - bulk or in 210L drums. He naturally wants to sell it to you.

1991 E34 //M5
2003 E55 AMG
2009 KTM 950 Super Enduro
2009 KTM 300 XCW
AfricaOffroad is offline  
post #3 of 332 Old 20th April 2008, 07:19 PM Thread Starter
derhammer
Member
 
derhammer's Avatar
 
Join Date: Aug 2006
Location: Canada
Posts: 44
Thanks: 1
Thanked 1 Time in 1 Post
Quote:
Originally Posted by AfricaOffroad View Post
A semi synthetic has a small percentage of Group 3 base oil in it - 10-20% IIRC.

Full synthetics comprise 100% Group 3 or Group 4 base oil. TWS is formulated with Group 4 (PAO).

TWS cannot even be compared to a Motul Semi Synthetic, the former is way way better in its lubrication properties. By way of example, normal group 1 base oil costs $1300per Ton. A group 3 costs about $2300per ton and a group 4 about $ 3500per ton. If oil companies could get the same lubrication properties with group 1s, believe me we would .

You dealer obviously has the Motul in stock - bulk or in 210L drums. He naturally wants to sell it to you.
Ok, thanks!.. but am I doing any wrong to the engine by running with that oil or should I switch to TWS again?
derhammer is offline  
post #4 of 332 Old 20th April 2008, 07:30 PM
AfricaOffroad
Senior Member (>500)
 
AfricaOffroad's Avatar
 
Join Date: Sep 2007
Location: South Africa
Posts: 526
Thanks: 85
Thanked 76 Times in 37 Posts
Look if it were me, I'd replace it as soon as convenient to do so.

Providing you are not driving your car hard, running up to the red line, or tracking your car, its probably okay. That said, that not how one drives a //M car is it?

1991 E34 //M5
2003 E55 AMG
2009 KTM 950 Super Enduro
2009 KTM 300 XCW
AfricaOffroad is offline  
The Following User Says Thank You to AfricaOffroad For This Useful Post:
derhammer (20th April 2008)
post #5 of 332 Old 20th April 2008, 07:46 PM
davidoli
M5 Expert (>4000)
 
Join Date: Aug 2006
Location: Suffolk
Posts: 7,455
Thanks: 1,079
Thanked 675 Times in 543 Posts
Fantastic response .......For a minute , I thought this was going to turn into another one of those inane oil threads .

It's suprising how many mechanics will base their advice on what suits their own purposes ........ thank god he didn't have a barrel of Planet oil in house !

Better a day as a tiger than a lifetime as a sheep !

91 Sebring 3.6 | E28 UK RHD M5 | E34 UK RHD 3.8 | E34 M5 Touring | E24 M635CSi UK RHD

www.classicmdautos.co.uk
davidoli is online now  
post #6 of 332 Old 20th April 2008, 07:47 PM
Dan Kelly
m5board.comoholic (>1000 posts)
 
Dan Kelly's Avatar
 
Join Date: Jan 2008
Location: Hertfordshire
Posts: 1,035
Thanks: 167
Thanked 223 Times in 155 Posts
I have been advised by someone who really knows their stuff that they have seen accelerated wear in S38 engines with 10w60 oil. BMW recommend 10w40 or 15w50 oils for this engine, I would stick to that.
Dan Kelly is online now  
post #7 of 332 Old 20th April 2008, 07:49 PM Thread Starter
derhammer
Member
 
derhammer's Avatar
 
Join Date: Aug 2006
Location: Canada
Posts: 44
Thanks: 1
Thanked 1 Time in 1 Post
Quote:
Originally Posted by Dan Kelly View Post
I have been advised by someone who really knows their stuff that they have seen accelerated wear in S38 engines with 10w60 oil. BMW recommend 10w40 or 15w50 oils for this engine, I would stick to that.
even if the car used synthetic oil in the past?
derhammer is offline  
post #8 of 332 Old 20th April 2008, 07:53 PM
Dan Kelly
m5board.comoholic (>1000 posts)
 
Dan Kelly's Avatar
 
Join Date: Jan 2008
Location: Hertfordshire
Posts: 1,035
Thanks: 167
Thanked 223 Times in 155 Posts
I would still use fully synthetic oil for the reasons stated by AfricaOffroad but would avoid using 10w60 and stick to recommended ranges.
Dan Kelly is online now  
post #9 of 332 Old 20th April 2008, 07:58 PM
AfricaOffroad
Senior Member (>500)
 
AfricaOffroad's Avatar
 
Join Date: Sep 2007
Location: South Africa
Posts: 526
Thanks: 85
Thanked 76 Times in 37 Posts
Quote:
Originally Posted by Dan Kelly View Post
I have been advised by someone who really knows their stuff that they have seen accelerated wear in S38 engines with 10w60 oil. BMW recommend 10w40 or 15w50 oils for this engine, I would stick to that.
Was that Raymond with the excessive cam lobe wear issue? If so, I suspect this relates more to the fact that occasional use allows the top end and oil channels to fully drain. On start up, top end could be a little oil starved for a few seconds.

If I lived in a cold climate, UK, Canada etc I'd definitely run a 0W?? (30 or 40), not a 15W. But it would be full synthetic (Group 4 based first choice, although 3 is also good stuff)

1991 E34 //M5
2003 E55 AMG
2009 KTM 950 Super Enduro
2009 KTM 300 XCW
AfricaOffroad is offline  
post #10 of 332 Old 20th April 2008, 08:08 PM
davidoli
M5 Expert (>4000)
 
Join Date: Aug 2006
Location: Suffolk
Posts: 7,455
Thanks: 1,079
Thanked 675 Times in 543 Posts
IIRC it was one of the BMW Motorsport division guys in Germany that recommended the use of Castrol Edge / TWS 10W60 specifically for the S38 engine .

Do you mind me asking who suggested otherwise to you ?

We need to consider that oil technology has moved on vastly from 1995 when the last of these S38 engines were put into E34 M5s and the owner's manuals produced .

Better a day as a tiger than a lifetime as a sheep !

91 Sebring 3.6 | E28 UK RHD M5 | E34 UK RHD 3.8 | E34 M5 Touring | E24 M635CSi UK RHD

www.classicmdautos.co.uk
davidoli is online now  
The Following User Says Thank You to davidoli For This Useful Post:
Spyder (24th June 2014)
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the BMW M5 Forum and M6 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes Rate This Thread
Linear Mode Linear Mode
Rate This Thread:



Similar Threads
Thread Thread Starter Forum Replies Last Post
Your maintenance cost vs. your car year myztikal47 E39 M5 and E52 Z8 Discussion 25 3rd February 2010 08:54 PM
Oil change andy777 E39 M5 and E52 Z8 Discussion 14 18th February 2008 03:28 AM
Burning Oil david enock E39 M5 and E52 Z8 Discussion 25 22nd May 2005 04:15 PM
Press Release no 2: The new V10 Power Unit in the BMW M6: A Masterpiece in Engine... Gustav E63 BMW M6 Forum and BMW M6 Convertible | m6board.com 0 15th December 2004 12:15 AM
Dealer says: New Serv. Bulletin Swtch to 10-60 w. capup E39 M5 and E52 Z8 Discussion 52 11th December 2002 03:05 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome