how much heat 5w30 can take?
- Thread starter Carguy80
- Start date
- Status
huh?
I hope most oils can "take" 100°C for short bursts (
)
I think I know what you are talking about and yes outside temp has little to do with oil running temp.
Does it get up to 38↑° in Sweden?
I hope most oils can "take" 100°C for short bursts (
I think I know what you are talking about and yes outside temp has little to do with oil running temp.
Does it get up to 38↑° in Sweden?
I think unless you live at the equator or death valley you should be just fine with a 30 weight oil. The philippines would need maybe a 40 weight as it is close to the equator and reaches above the 100 degree from time to time. In North Carolina we may have a few hours a year it reaches this temp and I have no worries using 5w30.
- Joined
- Sep 28, 2002
- Messages
- 39,793
The recommendation may have something to do "generically" with the 5w30's oils having a tendancy to shear. This is probably under the "recommended" factory oil change interval. My jeep has a qualification in the owners manual for 5w30 at sustained highway use where 85F (or was it 90F) temps are typical. That is, the 20 weight that a 5w30 will degrade to is not suitable where the highway usage will send the oil temps higher. Although ambient temp doesn't directly relate to oil temps ..it will usually index it higher or lower. They recommend a 10w30 with a preferred attached to it ..probably knowing that 5w30 is going to be the most offered oil in the service end of things.
Gary ,
Would a Group III 'synthetic' shear the same way a Dino 5w30 would in an engine that is driven hard ??
Would a Group III 'synthetic' shear the same way a Dino 5w30 would in an engine that is driven hard ??
The resultant lowered viscosity of a dino 5w30 is usually due to the "break-down" of the Viscosity Index Improvers.
I guess I need to get one of those Fahrenheit to Celsius conversion charts.
This is one area of oil temp ratings I still don't understand.
Yesterday it was below freezing on my drive home from work. Engine warms up and runs at 170-195 (as the thermostat does its job) on the way home.
In the height of summer, the engine will run 190-227, but usually right around 200, as the thermostat and fans do their job.
So why do we tell some people to run a thicker grade of oil in the summer? Is it just for those occasional spikes between the temp at which the thermostat opens and at the temp at the fans turn on??? I admit I sometimes use this logic myself, but it doesn't make sense to me. Coolant temp and oil temp are fairly close right?
Yesterday it was below freezing on my drive home from work. Engine warms up and runs at 170-195 (as the thermostat does its job) on the way home.
In the height of summer, the engine will run 190-227, but usually right around 200, as the thermostat and fans do their job.
So why do we tell some people to run a thicker grade of oil in the summer? Is it just for those occasional spikes between the temp at which the thermostat opens and at the temp at the fans turn on??? I admit I sometimes use this logic myself, but it doesn't make sense to me. Coolant temp and oil temp are fairly close right?
- Joined
- Sep 28, 2002
- Messages
- 39,793
As 427Z06 suggests, it's typically due to VII break down. Synths don't require much in terms of VII and won't show the
effects as much
We don't see too much loss of visc in the UoA section with synths in the absense of fuel dilution ..I don't know about the
driven hard issue
[ January 26, 2006, 02:53 PM: Message edited by: wwillson ]
Well, even if coolant and oil temps are not fairly close, the coolant in a sense is wrapping the internals in an insulating layer.
So if you suggest that the oil is a lot hotter than coolant during hard driving, I will agree. BUT it will be a lot hotter year round, not just in the summer.
So once again, why spec a thicker oil at the "high" end for summer? (the second number) Assuming the vehicle's cooling system is working correctly, I think oil temps would be the same once the engine is fully warmed up, whether we are talking the 120* equator or -20* Alaska.
Yes? No?
So if you suggest that the oil is a lot hotter than coolant during hard driving, I will agree. BUT it will be a lot hotter year round, not just in the summer.
So once again, why spec a thicker oil at the "high" end for summer? (the second number) Assuming the vehicle's cooling system is working correctly, I think oil temps would be the same once the engine is fully warmed up, whether we are talking the 120* equator or -20* Alaska.
Yes? No?
The manuals for my Toyota and Hyundai both advise 10w30 up to 100*F and xW-40 over that. In Australia we see temps over 100 occasionally, but I am using Mobil 1 10w30 in both as I do not wish to use a thicker oil, I have a feeling Mobil will be introducing 5w30 for use here shortly. xW-20 is not available here.
Roger
Roger
- Joined
- Sep 28, 2002
- Messages
- 39,793
Yes? No?
Maybe. Your oil temps are usually higher at highway speeds ..lower at idle. This is due to load and thermal input over time (less ignitions per minute). They tend to hang near coolant temps in a plus or minus manner ..but can be indexed for ambient temp where (typically) the oil pan is your only rejection medium. So, although your peak (steady state) oil temp will be @ 75 mph (after 13 miles or so) ..it may shift one way or the other depending on ambient temp.
There are, naturally, exceptions.
Maybe. Your oil temps are usually higher at highway speeds ..lower at idle. This is due to load and thermal input over time (less ignitions per minute). They tend to hang near coolant temps in a plus or minus manner ..but can be indexed for ambient temp where (typically) the oil pan is your only rejection medium. So, although your peak (steady state) oil temp will be @ 75 mph (after 13 miles or so) ..it may shift one way or the other depending on ambient temp.
There are, naturally, exceptions.
Depends on the vehicle and how it's driven among other factors. The only way to know for sure is to measure it.
bxd20, the oil temperature in my 4 cylinder Accord runs about 225° in 80° weather. It runs 195°-210° in 40-60 degree weather. In the 20's and 30's it hovers in the 190's.
I was once climbing Monida Pass in Idaho at 80 mph. The car was loaded with 3 200 lb. guys and our luggage, and the pass is 6800 ft, so the air is thin. I had it absolutely floored in 4th gear (5 spd manual transmission, about 4000 rpm) just to maintain speed, and it was cold enough outside that even with all that engine load and all those revs, the oil couldn't stay above 170°.
I've also gotten it as high as 245° climbing Blewitt Pass in the Cascades, and 240° idling in traffic with the A/C on. Both days were about 95°.
Those numbers make me a believer in different weights for different seasons. Based on how my car's oil temperature behaves, if I lived in a place with subzero winters and 100°+ summers, I'd run 5W-20 in the winter and 5W-40 in the summer. In a mild place like Washington, a 5W-40 or thick xW-30 would make me happy all year round.
[ January 27, 2006, 03:38 AM: Message edited by: Palut ]
I was once climbing Monida Pass in Idaho at 80 mph. The car was loaded with 3 200 lb. guys and our luggage, and the pass is 6800 ft, so the air is thin. I had it absolutely floored in 4th gear (5 spd manual transmission, about 4000 rpm) just to maintain speed, and it was cold enough outside that even with all that engine load and all those revs, the oil couldn't stay above 170°.
I've also gotten it as high as 245° climbing Blewitt Pass in the Cascades, and 240° idling in traffic with the A/C on. Both days were about 95°.
Those numbers make me a believer in different weights for different seasons. Based on how my car's oil temperature behaves, if I lived in a place with subzero winters and 100°+ summers, I'd run 5W-20 in the winter and 5W-40 in the summer. In a mild place like Washington, a 5W-40 or thick xW-30 would make me happy all year round.
[ January 27, 2006, 03:38 AM: Message edited by: Palut ]
- Status
Similar threads
