Viscosity REcommendations from Redline

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3,346
Location
Clarksville, Tennessee
Found this on the Redline site, which is what I would also personally concur to with Amsoil synthetics.
quote:
Red Line 15W50 & 20W50: The ultimate high-temperature protection in Red Line engine oils recommended for street use. Good for engines that regularly run very high oil temperatures. Best for engines that run large clearances such as air-cooled engines or large-displacement, all-out racing engines that see occasional street use. Provides 25% more viscosity in bearings than petroleum 20W-50s. Not recommended for use in cold climates where temperatures are at or below 10°F or -12°C. Not recommended for street use in production engines that see sustained oil temperatures below 225°F. Those engines should use Red Line 10W-30 or 10W-40.
I feel that Oil temp has a big impact on determining what viscosity you chose. I would also say that most cars in America rarely see oil temps over 225°F unless they are pullling heavy loads, or else they have some serious cooling problems. Even at 100° a mechaniclly sound engine should be able to keep the water temps below 200°, which I would gather would have oil temps at 212 or below. Sustain high speed driving over 110 miles per hour would significnatly raise oil temps, but where can you do this at, except on a track. Also I would also say if oil temps were to get to 225°, as long as it's 15 minutes or less, you should have no problems, especially if your using a high quality syn. like mentioned above. Now my question is why don't they put oil temp guages on cars???
 

Patman

Staff member
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21,989
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Oakville, Ontario
quote:
Originally posted by msparks:
quote:
Originally posted by Patman: Anyone who has an LT1 or LS1 Corvette with the oil temperature readout will confirm that these engines see 225+ oil temps when you're stuck in traffic.
I would say to that, your engine is not under any load, so the vis does not have to be as high to protect adequately. Also temps like that probably won't really even begin to degrade a good syn. Like you say, as soon as your under way, the engine immediately cools to a normal temp. My Triumph ST is the same way. Stop and go really gets it cooking, but once your moving about 10-15mph, it's good to go.

Good points Mike, I never thought of that. I guess the main thing to remember is to not drive the car very hard if I've been stuck in a traffic jam. It's then best to wait until I've driven on the open road a while and cooled things down. An oil temperature gauge is definitely something every single car (or at least high performance ones) should have! [ April 28, 2003, 01:52 PM: Message edited by: Patman ]
 
Messages
605
Location
Mississauga, Ontario
What do you guys think the temps would be in a high revving 4 banger at a lapping event? I've always used synthetic oil, 5w/10w30.. now the M1 0w40.. I would assume that going to M1 15w50 for the summer would not be recommended for a daily driven, (occasional track/auto-x) car..
 

MolaKule

Staff member
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21,698
Location
Iowegia - USA
They do come as options on some cars, but most are aftermarket. I would assume the manufacturer knows the range of oil temps for the average driving scenario so specifies the oil for the average temp range and engine clearances. Besides, synthetics have wider VI's, so they should not thin at high temps like dinos.
 

Patman

Staff member
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21,989
Location
Oakville, Ontario
Anyone who has an LT1 or LS1 Corvette with the oil temperature readout will confirm that these engines see 225+ oil temps when you're stuck in traffic. That's because unless you have the AC on, the second high speed cooling fan does not kick in until about 227F or higher, therefore you sit idling in traffic with that high coolant temp, which in turn heats up the oil too. At highway speeds it then drops right back down. I know my LT1 Firebird must see the same temps, but I have no oil temperature gauge to confirm (but I have confirmed that my coolant temps do go beyond 225F quite often when stuck in traffic without the AC on, not because of a cooling system problem, but simply like I said, the programming is setup from the factory to only turn on the second fan so high)
 

msparks

Thread starter
Messages
3,346
Location
Clarksville, Tennessee
quote:
Originally posted by Patman: Anyone who has an LT1 or LS1 Corvette with the oil temperature readout will confirm that these engines see 225+ oil temps when you're stuck in traffic.
I would say to that, your engine is not under any load, so the vis does not have to be as high to protect adequately. Also temps like that probably won't really even begin to degrade a good syn. Like you say, as soon as your under way, the engine immediately cools to a normal temp. My Triumph ST is the same way. Stop and go really gets it cooking, but once your moving about 10-15mph, it's good to go.
 
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