Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Reply
 
LinkBack Thread Tools Display Modes
Old 03-28-2014, 06:38 AM   #1
Registered User
 
Join Date: Apr 2011
Location: Alabama
Posts: 438
Blended Oil Cocktail, simple Q for smarter people

Ok, so I've started doing my own oil changes. My preference, after much review of the info here and elsewhere, is for Castrol Syntec 5w40, which is rare as hen's teeth around here.
Mobil 1 in 0w40 (Porsche approved) and 10w40high mileage is readily available and relatively cheap. If I blend the M1 0w40 and 10w40hm will this result in an appropriate 5w40 weight oil for my '01S?
Or suck it up, pay the extra, and order the Castrol in the correct weight?
Thanks in advance for the education.
BrokenLinkage is offline   Reply With Quote
Old 03-28-2014, 07:26 AM   #2
Registered User
 
Join Date: Feb 2005
Location: It's a kind of magic.....
Posts: 5,094
Quote:
Originally Posted by BrokenLinkage View Post
Ok, so I've started doing my own oil changes. My preference, after much review of the info here and elsewhere, is for Castrol Syntec 5w40, which is rare as hen's teeth around here.
Mobil 1 in 0w40 (Porsche approved) and 10w40high mileage is readily available and relatively cheap. If I blend the M1 0w40 and 10w40hm will this result in an appropriate 5w40 weight oil for my '01S?
Or suck it up, pay the extra, and order the Castrol in the correct weight?
Thanks in advance for the education.
Maybe. Different oil manufacturer's often start with completely different blend stock bases, then use their own additive packages to put the oil into the weight characteristics they want. So blending two different brands of oil could easily take you just about anywhere viscosity wise.

You would be vastly better off not playing "mad chemist" and buying the correct oil. Either go for the Castrol 5W-40, or better yet the Joe Gibbs DT 40.
__________________
Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein
JFP in PA is offline   Reply With Quote
Old 03-28-2014, 09:57 AM   #3
Beginner
 
Jamesp's Avatar
 
Join Date: Mar 2013
Location: Houston
Posts: 1,659
Garage
Quote:
Originally Posted by JFP in PA View Post
Maybe. Different oil manufacturer's often start with completely different blend stock bases, then use their own additive packages to put the oil into the weight characteristics they want. So blending two different brands of oil could easily take you just about anywhere viscosity wise.

You would be vastly better off not playing "mad chemist" and buying the correct oil. Either go for the Castrol 5W-40, or better yet the Joe Gibbs DT 40.
+1 based on memories of a fuels and lubes class I had about 30 years ago.
__________________
2003 S manual
Jamesp is offline   Reply With Quote
Old 03-28-2014, 10:26 AM   #4
Registered User
 
Join Date: May 2011
Location: Essex, CT United States
Posts: 299
Synthetic oils start with the lower viscosity base stock with an additive package that brings the higher viscosity when hot, dino oils the opposite.

That being said, I'd just buy the same oil across the board. I've been using M1 0W40.
__________________
2002 Boxster S, Arctic Silver, 18" Turbo Wheels, 6-speed
peterbrown77 is offline   Reply With Quote
Old 03-28-2014, 04:00 PM   #5
Registered User
 
rp17's Avatar
 
Join Date: Apr 2011
Location: DFW
Posts: 713
Don't mean to thread jack but, what about changing to the heavier oil around the summertime when it gets real hot, and then back to a say 0-40 for the cooler parts of the year? Use to do this on recommendations from a mechanic friend. But this was not on Porshes by the way.
__________________
What we're dealing with here is a complete lack of respect for the law.
rp17 is offline   Reply With Quote
Old 03-28-2014, 07:10 PM   #6
Registered User
 
Join Date: Apr 2011
Location: Alabama
Posts: 438
Thanks guys.
JFP's logic of different additives not having a cumulative effect on oil weight makes sense, and since there is no telling if Mobil 1 is consistent in using the same additives for viscosity throughout their line...
I'll steer clear of cocktails and boatdrinks for my car and just stick to a single malt beverage, paying extra and waiting a bit to get a good marque (Castrol Syntec) if I have the time, sipping the local (M1) brew if the time window is tight.
BrokenLinkage is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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




All times are GMT -8. The time now is 09:44 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page