Oil recommendations - Page 4 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Greenhornet2 · 04-25-2020, 07:40 AM

I don't believe in running a 15w. It is so thick on cold starts. I want my oil to flow as quickly as possible on a cold start to get everything lubricated asap. A 15w-40 and 5w-40 is the same viscosity at 210 degrees F but the 5w has the viscosity equivalent of a 5 weight in when freezing (still thicker than the 40 weight at operating temp). I can't figure out any reason not run run the lowest "W" rating that you can. If someone has a viable answer I'd like to learn. Everything I've researched has lead me to run the lowest "w" rating i can get that will provide the correct protection at operating temp. I could be wrong but i can't see why. If someone has any literature or info on that particular subject I'd love to read about it.

UNRIVALED SS · 04-26-2020, 07:45 AM

Flow as in volume is the most important factor. However, film strength and viscosity is relevant under high temp severe conditions. On paper 15w-40 and 5w-40 appear to be more similar than they are. One factor to consider, and understand that this is for the most severe conditions which most will never reach, the greater the difference between the hot and cold viscosity rating of a particular oil the more susceptible it is to shear. So, 5w-50 may seem like the perfect answer under extreme heat conditions for example, the shear strength of the oil film is actually very low.

Keep in mind Sprint Cup cars are running about 10 gallons of zero weight in their cars that scream at 9000 RPM for hours. I don`t remember the last time I saw a oil related failure on a cup engine.
Food for thought.

04-25-2020, 07:40 AM	#43
Greenhornet2 Drives: 2011 Camaro 2SS LS3 Whipple Join Date: May 2019 Location: Connecticut Posts: 1,925	I don't believe in running a 15w. It is so thick on cold starts. I want my oil to flow as quickly as possible on a cold start to get everything lubricated asap. A 15w-40 and 5w-40 is the same viscosity at 210 degrees F but the 5w has the viscosity equivalent of a 5 weight in when freezing (still thicker than the 40 weight at operating temp). I can't figure out any reason not run run the lowest "W" rating that you can. If someone has a viable answer I'd like to learn. Everything I've researched has lead me to run the lowest "w" rating i can get that will provide the correct protection at operating temp. I could be wrong but i can't see why. If someone has any literature or info on that particular subject I'd love to read about it. __________________ Whipple 2.9 CAI ID1050x injectors ZL1 Pump JRE FPCM JMS Voltage booster JRE Rough Idle blower cam BTR .660 springs CHE trunnion kit 1 7/8 Speed Engineering Borla Atak JRE scoop 1.5" lowering springs BMR trailing arms and toe links Cradle inserts 704WHP 603WTQ 93 octane

04-26-2020, 07:45 AM	#44
UNRIVALED SS Drives: 2010 Camaro SS Join Date: Aug 2010 Location: El Paso Posts: 704 View My Garage	Flow as in volume is the most important factor. However, film strength and viscosity is relevant under high temp severe conditions. On paper 15w-40 and 5w-40 appear to be more similar than they are. One factor to consider, and understand that this is for the most severe conditions which most will never reach, the greater the difference between the hot and cold viscosity rating of a particular oil the more susceptible it is to shear. So, 5w-50 may seem like the perfect answer under extreme heat conditions for example, the shear strength of the oil film is actually very low. Keep in mind Sprint Cup cars are running about 10 gallons of zero weight in their cars that scream at 9000 RPM for hours. I don`t remember the last time I saw a oil related failure on a cup engine. Food for thought.