Anyone know? I believe that this may be the reason I am having some consumption issues in a turbo application while in a hot climate.
NOACK of GC
- Thread starter Gilitar
- Start date
- Status
Well, I have had zero consumption with Syntec 5w40 in the very same application. I believe it was tooslick that said something about molecule size in making a 0wXX oil was to blame. I like the idea of a true synthetic and none of the readily available VW502 5w40 oils use a real synthetic base. I am starting to lean towards RL 5w40 VW 502 rating out the window.
Gilitar,
As just one example:
Amsoil 0w-30, Noack of 8.4%
Amsoil 5w-30, Noack of 6.6%
Amsoil 10w-30, Noack of 5.4%
Those are PAO stocks, but Group III's would follow the same general trend.
Higher molecular weight basestock blends simply evaporate less; reducing the # of polymeric thickeners also seems to reduce volatility. I suspect some of this VI modifier burns off as well.
Redline uses thicker basestocks and little or no polymeric thickeners. If it doesn't work for you, nothing will.
TS
I see near zero consumption with Redline.
I see some consumption with GC, probably a touch more than with M1.
GC is good stuff and I don't mind adding a few ounces every few K.
GC in my 5 year old Bimmer (90k) and zero comsumption on 5k oci's . Cheers! DV
Independent tests that I can share because they are older show:
RL 10w30 @ 5.66% 2004
Amsoil XL-7500 10w30 7.48% 2001
Amsoil 10w30 12.06% 2004
M1Supersyn 10w30 9.77% 2004
M1 Tri-Syn 10w30 6.65% 2000
M1 Advanced Formula 10w30 5.58% 2000
Anything less than 12-15% is just dandy for a PCMO in a engine that is well maintained.
quote:Tom made this point in another thread and I couldn't agree more. M1, has very low Noak, yet some experience more oil consumption with M1 than dino oils that are in the 13% range, vs M1's 6-9% range. I don't think you can always tie Noak to oil consumption. Like anything else, it's more involved than that. Terry thanks for sharing that data.
One other point -- volatility, whether measured by flash point or NOACK, is mainly an issue for the catalytic converter. It has little effect on oil consumption which is mostly a function of engine design, oil burning and leaks. Very little oil is lost to evaporation under normal driving conditions.
![[Cheers!]](/forums/graemlins/cheers.gif)
Some more data to munch on even though volatility of GC is not the cause of the consumption as Terry, buster, and Tom said:
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=51;t=000925
My consumption is only approx 1/2 qt per 3000 miles. I believe it is consuming the oil when oil temps get above normal due to the fact GC is a hair lighter than the 5w40 I previously used. I occasionaly drive the car fast (120 mph+) I bet the consumption is happening when the turbo heats the oil up....
Yeah high oil temps which thins the oil and high rpms which flings more oil into combuston chambers is a ripe condition for burning oil.
It's a combination of both viscosity and Noack volatility that typically determines oil consumption in service. Noack volatility has been a part of the API gas engine and diesel engine requirements specifically for this reason. Oils that break down chemically and form volatile compounds also tend to show higher oil consumption.
I believe the API/SM and API/CI-4+ spec limts for volatility are now 13%.
TS
I didn't know the speed limit went to 120 MPH in Alabama?? ![[Eek!]](images/icons/shocked.gif)
I think 120MPH is the blame for a half-quart loss in 3K.
I was just checking to make sure you guys were awake.... I'm just going to switch back to 5w40 since that seems to stop consumption.
- Status
