0W30 vs. 5W30 vs. 10W30

Messages
13,132
Location
By Detroit
All else equal, the 0w30 will have the most viscosity index improvers (VIIs) and will be most prone to breakdown under hard use, especially in summer. But all is not equal. In many cases it seems that as you look at the MSDSs for a brand, moving from 10w30 to 5w30 to 0w30 (if available), the base oil quality increases (base oil Group #). For example, MSDSs show Valvoline Durablend 5w30 to have more of the hydrotreat (Group II-III) than Durablend 10w30. This apparently is to equalize the performance across the different multigrades. If the higher group number has better cold propertied, then does a Group II 5w30 have as thick of a base oil as a Group I 10w30. I suspect not, but if it did, then the 5w30 would be the way to go. Maybe a Group IV 5w30 would. Wish there were a way to find out. Can't compare on cold crank or cold pumping viscosities as each different "w" number has a different temperature at which it is tested. Possibly the 40C viscosity would give a hint at the differences in the base oil weight.l But this would not be very accurate. [ August 10, 2004, 01:13 PM: Message edited by: TallPaul ]
 
Messages
13,132
Location
By Detroit
quote:
Originally posted by kickster: Assuming all these oils are synthetic then the VI sheering should not be a factor!
Yeah. True. Though some synthetic oils do use VIIs, perhaps a 5w40 or 5w50. But most synthetics should be pretty sheer stable. If I could run a 5w40 that had no VIIs I might do it, but it probably would be the cost-prohibitive Redline oil.
 

Patman

Staff member
Messages
22,000
Location
Guelph, Ontario
quote:
Originally posted by kickster: Assuming all these oils are synthetic then the VI sheering should not be a factor!
Exactly, we've got GC 0w30 which shows itself not to thin out very easily, except perhaps in turbo applications. In my old LT1 Firebird it would actually thicken up instead of thin out.
 
Messages
300
Location
toronto
what is the advantage of using a 5w30 or 10W30 over 0w30! since all 3 oils have same viscosity when they are hot then there is no point of using 10W or 5W!!! Am I missing something here?
 

Patman

Staff member
Messages
22,000
Location
Guelph, Ontario
quote:
Originally posted by JohnnyG: OK then, what's the story on GC? Does it have a lot of VII's or not? Final answer?
It appears that it uses very little, if any. Although it would be nice if we could get the full in depth voa on this stuff!
 
Messages
488
Location
Theodore Al
quote:
Originally posted by Patman:
quote:
Originally posted by JohnnyG: OK then, what's the story on GC? Does it have a lot of VII's or not? Final answer?
It appears that it uses very little, if any. Although it would be nice if we could get the full in depth voa on this stuff!

How much would it cost and how would you get that done?
 
Messages
2,635
Location
Chicago
Given that you are in Toronto you don't see too many 100+ degree days. If these are dino oils I would go with 5w30, if synthetic I would go with 0w30. Ideal would be 10w30 in the summer and 0w30 in the winter if the timing works out.
 
Messages
2,095
Location
IL
HTHS is more relevant that kinematic visc. And even then HTHS is not completely indicative of film thickness or shear resistance.
 
Messages
838
Location
Daytona Beach
Maybe we could take up a collection to help defer the cost. What are we talking here, Gas Chromatograph or what? Oppps [Eek!] Another GC! Go figure.
 
Messages
92
Location
Bay Area, CA
I drive a 2001 Acura Integra Type-R All conditions equal, and changing the oil religiously every 3000 miles, which Mobil 1 weight would theoretically be best for the engine: 0w-30 5w-30 10w-30 The cap says run 5w-30 and I do-- what potential 0w-30 advantages would I have?
 
Messages
2,387
Location
Chicago area
3000 m OCI with M1 is overkill - but I do the same thing - cheaper than a motor! Go with the 0-30, and you'll get better start up wear/oil flow, in addition to the great warm/hot protection.
 
Messages
92
Location
Bay Area, CA
Yeah, I know I'm throwing my oil away. Someone can pick it up from me if they want [Razz] Nah, but I drive it really hard (isn't that how a Type-R is supposed to be driven [Confused] ) but I like to treat it really really good maintenance-wise. I plan on changing the MTF every fifth oil change with Redline or Synchromesh, depending.
 
Messages
80
Location
North Hollywood
Well...from what I read you should see some UOA's on the vis/brand/engine and try and make a decision that way. You could use a 0W-30 and think your getting less wear at startup, but if a UOA's shows a 10W-30 with less wear, then the 0W-30 theory would be bunk for your engine. Also lowest outside starting temp plays a big factor. I live in Los Angeles and the difference between a 0W-30 and a 10W-30 during startup in null imho.
 
Messages
11,247
Location
PA
quote:
All conditions equal, and changing the oil religiously every 3000 miles, which Mobil 1 weight would theoretically be best for the engine: 0w-30 5w-30 10w-30
GC! [Razz]
 
Messages
2,387
Location
Chicago area
I'd sure like to se a condemning UOA on someone's engine oil that ran M1 0-30 and changed it every 3000m. I mean, once you are up to 3-400,000m of engine life, when do you proclaim an oil is OK? Especially between extremely similar hot temp weight oils.
 
Messages
841
Location
Ohio
quote:
Originally posted by Patman:
quote:
Originally posted by kickster: Assuming all these oils are synthetic then the VI sheering should not be a factor!
Exactly, we've got GC 0w30 which shows itself not to thin out very easily, except perhaps in turbo applications. In my old LT1 Firebird it would actually thicken up instead of thin out.

Thickening is not good either and is an indication of a lack of high temp stability based on what I've read.
 
Top