Lowest safe starting/operating temps for oil

[hi-miler]

I know this is probably easy to find, but after searching for a while, I'm asking for help.
I've been asked a question on another board concerning the lowest safe starting/operating temp for 20w-50 oil in an air cooled engine with wet clutch. Specifically synthetic, but I would be interested in the comparison between syn and dino.
Also, any similar input on Amsoil MCV 20w-50?
Thanks
Steve

 

[Eddie]

I would probably look at the pumpable temperatures listed in the product specs for a start to compare.

 

[PT1]

I don't start my Harley if it is below 40f with 20w50 which I always use. The reason...I don't ride under 40f so why take the engine wear from a cold start. If you ride under 40f I would use Mobil1 15w50 for a Winter oil. I don't care what the specs say because below 40f you can hear the valvetrain banging away for a minute with 20w50. JMHO

 

[BuickGN]

With a real oil pressure guage on my GN I can't tell the difference in time to pressure from a 20-50 to a 5-30 that I used once. I only run 20-50 and 15-50 and have had no problems in freezing temps. I do give it a few minutes of warmup and wait until the pressure comes off of the 70psi relief before I touch the throttle.

 

[Audi Junkie]

I have a silly rule/guideline I made-up that applys well to the lighter oils, maybe your 20w too.

below 0f=0w
about +5f=5w
about +10f=10w
about +15f=15w
So, @+20f=20w

 

[Drew99GT]

I think it's generally accepted that 20 degrees F is the lowest safe starting temp for conventional 20W-50, but Amsoil will be better since it's synthetic.

 

[hi-miler]

Thanks Drew, That's the number I'm looking for, althought the Honda Rebel 250 shop manual says it's good down to 32 degrees F.
Synthetic has to be much better than that, but how much?
Steve

 

[Propflux01]

Wouldnt really recommend running a 20w-50 in that 250, 5w-40 like rotella Synth or something like that would be much better IMHO..

 

[PT1]

Originally Posted By: Audi Junkie
I have a silly rule/guideline I made-up that applys well to the lighter oils, maybe your 20w too.

below 0f=0w
about +5f=5w
about +10f=10w
about +15f=15w
So, @+20f=20w


My rule guideline for 20w50 in my motorcycle is below 40f= I'm inside watching tv. Below 30f I have the fireplace lit as well.

 

[RWEST]

Quote:
My rule guideline for 20w50 in my motorcycle is below 40f= I'm inside watching tv. Below 30f I have the fireplace lit as well.

And, a good rule that is!!

I read about guys riding when it's below freezing and wonder ......... why?

 

[hi-miler]

For guys up in Canada 32 degrees F. is no big deal to them. Heck, they would have almost no riding season if they didn't ride below 40 deg. F.
Question still stands though. Anybody know of any data on the lowest safe starting/operating temp. for conventional and synthetic 20w-50 oil?
Some well reasoned answers out there, but no real written guidelines to look at yet.

 

[sunruh]

according to the manual on my MMoD. 20w50 can be used between 10 and 45C (ie 50 - 113F).

now i'm not saying that is the usable range, just what the manual says. i've safely used it to 40F, but i would not want to go lower if i could help it. by the same token i've pushed the 113F as well.

i think i would rather ride in the snow, than run over copperheads on the trail like i did last weekend. just like this one.

 

[RWEST]

Quote:
i think i would rather ride in the snow, than run over copperheads on the trail like i did last weekend. just like this one.
YIKES!!

Looks suspiciously like something I rode past a couple weeks ago on PA Rt. 326 just south of Rainsburg. Ick!! Fortunately, its head had been previously flattened by a car or something.

One of the guys at the Suzuki forum told about a highway ride they were on through the back country of Arkansas or somewhere - a rattlesnake struck at one guy when he went by, and the next guy ran over it (the snake). Then, of course, the thread deteriorated into what's the best way to prepare snake, grilling or frying, etc....

 

[sunruh]

i ran over it with both wheels. turned around to get a better look. didn't see the barbwire laying the brush. had it wrap around my front wheel and spent almost 15min getting it out. only to find the snake gone. so he must be fine.

i've probably ran over 6 or so rattlers. they are easier to spot because of the tail. this guy was barely in the sun and looked like a stick and some leaves which are all over the place. never hit a copperhead before. he looked small. about 2 - 2.5 feet long maybe.

and word to the wise, you want to brake slide over them, *NOT* roost them onto your back seat by hammering the throttle!!!
knobbies will pick them up and lay them next to your butt with an angry attitude.

 

[Drew99GT]

Originally Posted By: hi-miler
For guys up in Canada 32 degrees F. is no big deal to them. Heck, they would have almost no riding season if they didn't ride below 40 deg. F.
Question still stands though. Anybody know of any data on the lowest safe starting/operating temp. for conventional and synthetic 20w-50 oil?
Some well reasoned answers out there, but no real written guidelines to look at yet.


Well, by definition, the SAE 20w test is done at 5 degrees F for cold cranking and -4 degrees F for cold pumping. So 5 degrees F is the absolute lowest temp you want to safely start an engine with a conventional 20w-50 oil since at that temp, the engine will safely crank and the oil will safely pump. But that's at the margin. It used to say right on the bottle of Castrol GTX 20w-50 to use above 20 degrees F.

Amsoil 20w-50 motorcycle oil doesn't list the CCS and MRV specs but it does have a -39 degree F pour point.

As stated above, a 5w-40 like Rotella would be a much better oil to use in cold weather.

You can also find 5w-50 oils and there is always Mobil 1 15w-50.

 

[sunruh]

my tests have shown that Castrol Syntec 0w30 (ie GC) to be a very robust oil that can handle a bike.

 

[wileyE]

We ride offroad here in the 20's and 30's . 20w50-60w has huge clutch drag until it gets hot. Some guys even have a hard time cold starting the bike and partially blame the oil. Not uncommon for guys (especially ktm's and huskys on 60w) to lean their bike against the truck with the tailpipe of the truck pointing at the engine case while they get their gear on, some even throw a tarp over it.

 

[hi-miler]

Thanks Drew & Wiley
This is the type of info I'm ultimately looking for. The guy who wants to know this wants to purchase a case of oil at a time and is interested in what the lowest temp he can run the 20w-50. I feel confident now in in using this info to tell him he's safe to well below freezing with synthetic 20w-50.
Question though, why isn't this type of information readily available? My first thought is that it might be a engine specific answer. Any other?
Steve
PS I go camping with the Boy Scouts quite a lot, you get used to the snakes, spiders, etc.. Been bit by this and that kind of small insect including spiders (no Black Widows or Brown Recluse) more times than I can remember. It's not the snakes and such that irritate me, it's the darn poison ivy!