I've been reading a lot more about oil on this site than I ever expected. Tons of info here, but I figured I'd post a question or two.
I have a 2009 Saab 9-5 wagon that I bought a few months ago with about 85,000 miles on it (runs pretty well, no oil consumption, but can be a bit noisy when giving moderate-high power). I've used Mobil 1 in my cars for years, just because it's good and readily accessible. Apparently, the Saab needs GM-LL-A-025 oil, which Mobil 1 does not meet, so I thought I’d look at other brands. Oil grades in the owner's manual are 0w30, 0w40, 5w30, 5w40. I change the oil at about 5,000-6,000 miles. Driving is mostly commuting, occasional stop-and-go, occasional road trips (with medium/somewhat heavy car loads) usually to New York City (thus “aggressive” driving required), I try to keep it under 3,000 rpm.
After much searching, I thought I'd try Amsoil (which I used for a while many years ago). However, not all of their oil meets GM-LL-A-025. I was planning to get 5w40, figuring the thicker oil will give a bit better protection. 0w40 is another option, but winters for me aren't too cold (perhaps 10*F on occasion, 0*F rarely). I figure 5w synthetic should be fine. The other option is 5w30, which seems a bit thin to me.
So, I'm trying to decide between:
5w40 European AFL (meets Dexos 2)
5w30 Signature Series (meets GM-LL-A-025)
0w40 Signature Series (meets API SN SM)
Only the 5w30 Signature meets the GM-LL spec, although the 5w40 meets Dexos 2, which replaced the GM-LL spec (sort of). Here are the numbers from Amsoil’s product data sheets:
Spec 5w40 Euro AFL 5w30 Signature 0w40 Signature
Kinematic Visc. 100C 14.3 10.3 14.8
Kinematic Visc. 40C 88.5 59.7 84.6
Viscosity Index 168 162 184
CCS Viscosity 5855 (-30) 3968 (-30) 6062 (-35)
Pour Point -40C -50C -50C
Flash Point 224C 220C 222C
Fire Point 240C 244C 238C
Four-Ball Wear Test 0.44 N/A N/A
NOACK Volatility 10% 6.7 7.7
HT/HS Viscosity 3.8 3.11 3.76
TBN 8 12.5 12.5
From what I’ve read, it sounds like the Signature series is the better line of oils. From these numbers, the 5w40 European looks pretty good, except for the high NOACK and low TBN (relatively). The 5w30 Signature has better CCS, NOACK, and TBN, but lower HT/HS.
So, I’ve got a few questions:
1. How much more protection would 5w40 (or 0w40) provide over 5w30? Does the thinner 5w30 help with engine cooling (especially in summer traffic)?
2. How much difference is there in protection between HT/HS 3.1 and 3.8?
3. Is the GM-LL-A-025 spec is just for extended oil change intervals (and thus the 0w40 Signature is an option, although its CCS is high)? Or does it indicate things like SAPS level, etc?
4. Is the Signature Series better than the European line? If so, what’s the difference? (better heat tolerance? better film layer for startup? etc)
5. Does anyone know if my car needs low, mid, or high SAPS? Amsoil's website says mid-SAPS, based on the GM-LL-A-025 spec called for in the owner's manual.
Thanks in advance. (sorry for the long post)
I have a 2009 Saab 9-5 wagon that I bought a few months ago with about 85,000 miles on it (runs pretty well, no oil consumption, but can be a bit noisy when giving moderate-high power). I've used Mobil 1 in my cars for years, just because it's good and readily accessible. Apparently, the Saab needs GM-LL-A-025 oil, which Mobil 1 does not meet, so I thought I’d look at other brands. Oil grades in the owner's manual are 0w30, 0w40, 5w30, 5w40. I change the oil at about 5,000-6,000 miles. Driving is mostly commuting, occasional stop-and-go, occasional road trips (with medium/somewhat heavy car loads) usually to New York City (thus “aggressive” driving required), I try to keep it under 3,000 rpm.
After much searching, I thought I'd try Amsoil (which I used for a while many years ago). However, not all of their oil meets GM-LL-A-025. I was planning to get 5w40, figuring the thicker oil will give a bit better protection. 0w40 is another option, but winters for me aren't too cold (perhaps 10*F on occasion, 0*F rarely). I figure 5w synthetic should be fine. The other option is 5w30, which seems a bit thin to me.
So, I'm trying to decide between:
5w40 European AFL (meets Dexos 2)
5w30 Signature Series (meets GM-LL-A-025)
0w40 Signature Series (meets API SN SM)
Only the 5w30 Signature meets the GM-LL spec, although the 5w40 meets Dexos 2, which replaced the GM-LL spec (sort of). Here are the numbers from Amsoil’s product data sheets:
Spec 5w40 Euro AFL 5w30 Signature 0w40 Signature
Kinematic Visc. 100C 14.3 10.3 14.8
Kinematic Visc. 40C 88.5 59.7 84.6
Viscosity Index 168 162 184
CCS Viscosity 5855 (-30) 3968 (-30) 6062 (-35)
Pour Point -40C -50C -50C
Flash Point 224C 220C 222C
Fire Point 240C 244C 238C
Four-Ball Wear Test 0.44 N/A N/A
NOACK Volatility 10% 6.7 7.7
HT/HS Viscosity 3.8 3.11 3.76
TBN 8 12.5 12.5
From what I’ve read, it sounds like the Signature series is the better line of oils. From these numbers, the 5w40 European looks pretty good, except for the high NOACK and low TBN (relatively). The 5w30 Signature has better CCS, NOACK, and TBN, but lower HT/HS.
So, I’ve got a few questions:
1. How much more protection would 5w40 (or 0w40) provide over 5w30? Does the thinner 5w30 help with engine cooling (especially in summer traffic)?
2. How much difference is there in protection between HT/HS 3.1 and 3.8?
3. Is the GM-LL-A-025 spec is just for extended oil change intervals (and thus the 0w40 Signature is an option, although its CCS is high)? Or does it indicate things like SAPS level, etc?
4. Is the Signature Series better than the European line? If so, what’s the difference? (better heat tolerance? better film layer for startup? etc)
5. Does anyone know if my car needs low, mid, or high SAPS? Amsoil's website says mid-SAPS, based on the GM-LL-A-025 spec called for in the owner's manual.
Thanks in advance. (sorry for the long post)
