Ambient air temp over 105 every day

[zray1]

Is there any advantage to using Mobil 1 5w-40 vs Mobil 1FS 0w-40

Will be putting 5,000+ miles on the car before temps get down to the 90’s.

The car is a 2002 Jaguar XKR, supercharged 4.0 liter V-8, that has a typical oil temp in the summer of 215 F to 240 F. Coolant temp generally 15-20 F less than the oil temperature.

Z

 

[DemoFly]

Their viscosities will be basically the exact same.

 

[Brian123]

Is there any advantage to using Mobil 1 5w-40 vs Mobil 1FS 0w-40

Will be putting 5,000+ miles on the car before temps get down to the 90’s.

The car is a 2002 Jaguar XKR, supercharged 4.0 liter V-8, that has a typical oil temp in the summer of 215 F to 240 F. Coolant temp generally 15-20 F less than the oil temperature.

Z

If you drive the car like Grandma, there might not be an advantage, but now that I am addicted to HTHS Numbers, I would see which oil has a better HTHS Number. I am guessing 5W-40!

 

[edyvw]

Again, just bcs. you are hot, that does not mean engine oil is. Oil temperature is controlled by a coolant system and potentially air-cooled oil cooler.
I tracked the car with Mobil1 0W40 and had oil temperatures hitting 300f. I kept oil for 5,000mls in.

 

[zray1]

If you drive the car like Grandma, there might not be an advantage, but now that I am addicted to HTHS Numbers, I would see which oil has a better HTHS Number. I am guessing 5W-40!

I’m guilty of not driving like grandma.

This car is my first modern type car. Which I define as fuel injected & electronic everything, etc. I intend to make the most of driving experiences for however much time I’ve got left

I had to give up my classic Shelby’s and assorted old British cars due to old back injuries that finally caught up with me. I fell off too many motorcycles in the ‘70’s). My clutch leg has pushed in its last clutch

 

[zray1]

Again, just bcs. you are hot, that does not mean engine oil is. Oil temperature is controlled by a coolant system and potentially air-cooled oil cooler.
I tracked the car with Mobil1 0W40 and had oil temperatures hitting 300f. I kept oil for 5,000mls in.

So my oil temperature of 240 F is not a problem and is well within the 0w-40 comfort zone.

How long is your oil temperature sitting at 300 F ? My cross country driving is generally an all-day affair with oil temps varying quite a bit as I transition from 2 lane rural roads to small city stop-and-go traffic.
Is that harder on the oil than a racing situation that has higher oil temps, but for a shorter time frame ?

PS: FWIW, the car does have a factory equipped oil cooler

 

[edyvw]

So my oil temperature of 240 F is not a problem and is well within the 0w-40 comfort zone.

How long is your oil temperature sitting at 300 F ? My cross country driving is generally an all-day affair with oil temps varying quite a bit as I transition from 2 lane rural roads to small city stop-and-go traffic.
Is that harder on the oil than a racing situation that has higher oil temps, but for a shorter time frame ?

Oil has to be at 220f minimum. That is desirable. The open road is very easy on oil.
Here is UOA of 5k on 5W30 Motul X-Clean+ in my Atlas. We did 4,073 miles of road trip, and the oil temperature in some situations was going around 260f. Total miles on oil are 5,182. While 300f is for a shorter period of time, it is the temperature where limits are pushed.
Also, you have this confused. Both oils you mention are 40 grade. In Mobil1 line up, 0W40 is designated as track-acceptable oil, and 5W40 is not mentioned.

 

[edyvw]

By the way, Porsche is using Mobil1 0W40 in Daytona etc.

 

[zray1]

Thank you . I do realize that both oils are 40 wt. I should’ve phrased my question differently. What I’m asking is, are the additive packages of any substantial difference that would make one oil better suited to summer driving where the oil temp is approaching 250 F

You answered my question somewhat with the post mentioning that the 0w-40 has a “track acceptable” designation. Thanks again for the detailed reply

Z

 

[zray1]

Regarding the oil’s minimum temp:

The oil cooler on the XKR has its own thermostatically controlled diverter valve. It keeps the oil from going thru the oil cooler until it reaches a (minimum) temp of 217 F to 226 F:

From the shop manual:

This valve is fitted between the oil pump outlet and the oil filter inlet.

The oil diverter valve operates thermostatically and at higher temperatures diverts the oil through the oil cooler. The valve begins to open between 103°C and 107°C and is fully open, diverting 100% of the oil, at 119°C.

( begins to open : 217 F to 226 F
Fully Open: 246 F ).

 

[edyvw]

Thank you . I do realize that both oils are 40 wt. I should’ve phrased my question differently. What I’m asking is, are the additive packages of any substantial difference that would make one oil better suited to summer driving where the oil temp is approaching 250 F

You answered my question somewhat with the post mentioning that the 0w-40 has a “track acceptable” designation. Thanks again for the detailed reply

Z

Search what is HTHS. That is key value. It is not grade per se. Both oils you mentioned have minimal HTHS of 3.5cP. M1 0W40 is 3.6 and 5W40 is 3.7. Higher HTHS (which is measured at 150c) better protection. For example, Motul X-Cess 5W40 I use has HTHS of 3.8. But, higher HTHS=more resistance =more heat. Add to that additive pack which in M1 is cutting edge. On street you will never, ABSOLUTELY never, reach a point where you will overwhelm that oil. You showed 131mph. That is nothing. Think that that is normal speed for some 1.4 turbo engine in Germany and that it perhaps doing it every day.
Also, ambient temperature is not an issue, altitude is. You have air oil cooler, you are set.