Viscosity Where 5W30 Has Sheared Out of Grade?
- Thread starter Islander
- Start date
- Status
There is a viscosity chart on the main page.
The bottom range for a 30 weight is 9.3 at 100C. So if your below that, your out of grade into a 20.
I notice than some 10w30's also shear down to below 9.3 cSt. The good news is that it does not seem to increase wear numbers. I wonder if Ford and Honda realized that most of us using 5w30 dino were already running "5w20" without harming our engines?
Hmmm....interestingly enough, I havent' seen any of the 20 weights shear down to 10's....
That's at the heart of the 20 weight question--does it start out life too thin to begin with so that when it begins to shear down over time does it shear down significantly enough to compromise film strength and accelerate engine wear and at what mileage does this begin to occur? Comments welcome!
The UOA's so far have been very good on the 20's. Do a search on UOA page and get many examples showing just that.
At this point one either believes what the UOA's show...that the 20's hold up where specified, OR one doesn't believe what they read and will probably never accept and will always look for a reason not to use/question the use of a 20 oil.
At this point one either believes what the UOA's show...that the 20's hold up where specified, OR one doesn't believe what they read and will probably never accept and will always look for a reason not to use/question the use of a 20 oil.
Judging solely by my own experience with 5w-20 (Havoline to be specific), there has been no evidence of the 20w shearing down and out of grade. Look here http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=002450 and you can see that for the three samples I've had analyzed, all have stayed solidly in the 20w region and at varying intervals. I believe it was the second sample that had some road course track use and still remained solidly in grade.
I'm not saying this is the case with all 20 weights and all engines but for my particular vehicle shearing doesn't seem to be a problem.
Tenderloin......well said
The most recent 5w-30 UOA's here show the current formulations don't shear out of grade.
Oil companies want to sell their oils to the auto manufacturers so they're all making quality 5w-30 because that's what manufacturers spec for many new cars.
Oil companies want to sell their oils to the auto manufacturers so they're all making quality 5w-30 because that's what manufacturers spec for many new cars.
The current formulation (GF-4) of Mobil Drive Clean was on the verge of shearing out of grade in my STi (2,500 OCI):
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=002305#000000
It also sheared out of grade on Tim's STi (2,210 OCI):
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=1;t=009004
Granted, these are high-horsepower turbocharged engines, but I was expecting better given the low OCI. YMMV.
It looks like those UOA's mentioned included lube-control and is that a dino or synth/synth blend? It seems that all the good 5w-20 UOA's have either been synthetics or synthetic blends--I'd like to see some 4-5K UOA's on some common dino 5w-20's. I want to start using dino 5w-20 with 3,000 mile OCI's but I'm concerned about shear stability/film strength, especially in the hot summer months.
Due to the GF-4 volatility requirements, 5W-20's are most likely formulated using Grp II/III blends. Motorcraft 5W-20 is the prime example and is a "dino-syn" blend and does not contain PAO or ester basestocks.
Chevron/Havoline & Pennzoil 5W-20's may be all GRP II+ - I'm not really sure. Regardless, the performance is similar, additives make up the difference, & I would'nt be concerned about whether the base oil is 118 or 124 VI.
Chevron/Havoline & Pennzoil 5W-20's may be all GRP II+ - I'm not really sure. Regardless, the performance is similar, additives make up the difference, & I would'nt be concerned about whether the base oil is 118 or 124 VI.
I plan on trying Exxon Superflo 5W-20 in my 1995 Maxima but was going to wait until after the summer--the thought of using such a relatively thin oil in 95 degree summer heat in bumper to bumper freeway traffic with the A/C on full blast concerns me and I'm not willing to shell out the extra bucks for s synthetic/synthetic blend.
Made me double check and glad I did. Here are a couple of links that provide good info as to the makeup of Havolne 5w-20/5w-30 (and other useful info). Looks like both those grades are in fact a GII/GII+ mix. Interesting thing is that according to ChevronTexaco all their GII and GII+ base oil are hydroprocessed yet only the 5R in that table specifically states hydroprocessed
Here are the links;
http://www.chevron.com/prodserv/baseoils/products.shtml
http://www.chevron.com/prodserv/baseoils/gf4.shtml
http://www.chevron.com/prodserv/baseoils/grp2_typical.shtml
mikep or anyone else that can help...
I've been trying to find a durable dino oil to use for HPDEs like mikep has and I'm wondering if 5w30 or 10w30 would be as durable as his 5w20? :keeps searching....:
I've been trying to find a durable dino oil to use for HPDEs like mikep has and I'm wondering if 5w30 or 10w30 would be as durable as his 5w20? :keeps searching....:
- Status
Similar threads
