Mobil 1 FS 0w40 vs 5w40 vs 5w50 vs 15w50 in a modified LT4 in warmer climate??

[Neversatisfied02]

Alright guys,
I’m working nights tonight so I figured I’d make a new post to help narrow down the remainder of my options with some more input from you guys.

My previous post was in regards to the Mobil 1 0w40 ESP/Supercar Dexos 2 requirement on the ZL1, Z06 and CTS-V for the LT4. From that post, I’ve been able to conclude that Dexos 2 is strictly an emissions based requirement and its purpose is solely to protect the cats/warranty as I suspected all along. On a modified vehicle with cats removed and having no warranty like mine, there are plenty of other options to choose from oil wise.

Now… my car is modded (heads/cam/Whipple,etc) and makes over 900rw. It is currently on the stock bottom end. Car is a weekend driver that sees some spirited driving on the street when it’s taken out. It might make a trip to the drag strip at some point but it’s mainly a street toy. Car has an 160* stat. Oil temps see 200ish at times. Back to back pulls might get it over that but it wouldn’t be by too much if so. I live in Houston, TX where we have warmer weather nearly year round minus the few months it gets a little cooler in which case… it’s rare to see freezing temps (32* or below). Usually we’ll dip into the higher 30’s the odd time and that’s about it.

I know the Mobil 1 FS 0w40 euro oil is a solid option which I’m strongly considering for the sake of being the same weight that’s recommended.

Among my other considerations are…
Rotella T6 5w40
Mobil 1 FS 5w50
Mobil 1 FS 15w50

To be honest… I’ve narrowed it down to these for a couple of reasons. The mobil 1 oils show some good stats on their full SAPS stuff and it’s easily obtainable locally at a good price. Considering I change the oil at 2k miles on average (due to running E85 and meth), I’m not looking for anything with an extended OCI. I’m just trying to decide which oil would work best for my setup, driving style and ambient temps when it comes to protection.

 

[edyvw]

Ambient temperature is not an issue. If you lived at a high altitude like here, maybe, consider hp.
Go Mobil1 0W40FS. You do not see track, so do not overthink.

 

[Neversatisfied02]

Ambient temperature is not an issue. If you lived at a high altitude like here, maybe, consider hp.
Go Mobil1 0W40FS. You do not see track, so do not overthink.

Ok. Yeah… that’s what I was leaning toward. I figured the good flow at startup of the 0w and the protection of the 40 was prob good enough to just switch to the euro Mobil 1 FS 0w40. Basically the same as what I’ve been using but with full SAPS.

Only reason the T6 was a consideration is because I’ve got a bunch of it and I use it in my diesel and some other vehicles. Figured the 5w40 wouldn’t be a bad move either since temp here in Houston wouldn’t affect it either way between 0w and 5w.

5w50 sounded good for the same purpose but with more higher temp protection and of course the 15w50 being recommended for track use put it on the list too.

But… you’re right. The 0w40 is prob enough for what I’m doing with the car.

 

[edyvw]

Ok. Yeah… that’s what I was leaning toward. I figured the good flow at startup of the 0w and the protection of the 40 was prob good enough to just switch to the euro Mobil 1 FS 0w40. Basically the same as what I’ve been using but with full SAPS.

Only reason the T6 was a consideration is because I’ve got a bunch of it and I use it in my diesel and some other vehicles. Figured the 5w40 wouldn’t be a bad move either since temp here in Houston wouldn’t affect it either way between 0w and 5w.

5w50 sounded good for the same purpose but with more higher temp protection and of course the 15w50 being recommended for track use put it on the list too.

But… you’re right. The 0w40 is prob enough for what I’m doing with the car.

Mobil1 0W40 is also recommended for the track. I ran it at HPR here, where cooling of an engine or lack of is the name of the game, considering altitude (5,000ft). Before installing the oil cooler, I ran 300f oil temperature in BMW with that Mobil1, with excellent results, and ran it for 5k.

 

[Neversatisfied02]

Mobil1 0W40 is also recommended for the track. I ran it at HPR here, where cooling of an engine or lack of is the name of the game, considering altitude (5,000ft). Before installing the oil cooler, I ran 300f oil temperature in BMW with that Mobil1, with excellent results, and ran it for 5k.

Great to hear! If it worked that well for you… I imagine it’ll work just as well for me. Can’t beat the fact it’s readily available at the local Walmart also! 😬

 

[edyvw]

Great to hear! If it worked that well for you… I imagine it’ll work just as well for me. Can’t beat the fact it’s readily available at the local Walmart also! 😬

Your oil temperature is low. You really do not want anything thicker than this M1 0W40.

 

[userfriendly]

Your oil temperature is low. You really do not want anything thicker than this M1 0W40.

I was wondering about the logic behind the 160 thermostat, especially with E85.

 

[Neversatisfied02]

I was wondering about the logic behind the 160 thermostat, especially with E85.

That’s the main reason I’m not fighting the higher coolant/oil temps. In summer weather and with spirited driving, temps were obviously higher with the factory 195* stat or whatever it is. I ran the same 160* stat on both my C7Z and the V with no issues at the recommendation of the shop.

 

[userfriendly]

That’s the main reason I’m not fighting the higher coolant/oil temps. In summer weather and with spirited driving, temps were obviously higher with the factory 195* stat or whatever it is. I ran the same 160* stat on both my C7Z and the V with no issues at the recommendation of the shop.

Is it possible that a hotter engine, water and oil removes more heat from the engine?

 

[Neversatisfied02]

Is it possible that a hotter engine, water and oil removes more heat from the engine?

I’m not 100% sure on what you’re asking.

The lower temp thermostat just allows the coolant to flow sooner. Everything still works the same. It just gives more of a buffer when temps are elevated from beating on the car. Instead of being nearly 200* already and climbing… I’ve got that 20* offset. I know people who run no thermostat at all. 🤷🏻‍♂️ But yes, the cooler water and oil temps def help with cooling the motor.

 

[userfriendly]

I’m not 100% sure on what you’re asking.

The lower temp thermostat just allows the coolant to flow sooner. Everything still works the same. It just gives more of a buffer when temps are elevated from beating on the car. Instead of being nearly 200* already and climbing… I’ve got that 20* offset. I know people who run no thermostat at all. 🤷🏻‍♂️ But yes, the cooler water and oil temps def help with cooling the motor.

I know people that remove engine thermostats too, usually found at drag strips.
I'm not sure what the board response will be today, but a flame proof suit is advisable.

 

[userfriendly]

www.onallcylinders.com

go to search and type; losing your cool 9 cooling system myths and mistakes.
The best part is all the comments below the article.

 

[ka9mnx]

Warmer engines are more efficient engines. Oil not getting up to temperature is not a good thing. If your oil temperatures are going above 250F then you might have a problem. Over 300F on the street is very problematic. You are doing no good to your engine, and oil, using a 160F thermostat. You engine oil should run consistently around 212F.

 

[thescreensavers]

The cooler thermostat doesn't make the engine run cooler just causes it to take longer to warm up.

Lot of American cars shops throw the lower thermostat on, very common on the forums as a "mod". Always laughed when I saw that when I had my Camaro.

On track I was seeing 285F oil temps LT1(Dexos2 5W40), I'm sure the ZL1/V is seeing similar temps in a track setting. But on the street 200 is normal operating temp.

 

[edyvw]

I also agree about thermostat. Yoh really want to above 200 ASAP. After that, it is cooling capacity to maintain it.

 

[OVERKILL]

I recall a study done years back that showed a 180 to be "ideal" from a wear perspective. A 160 was too cold and increased wear, while a 190 would result in ignition timing getting pulled, but having basically the same wear rate as the 180. Of course, this (timing getting pulled) would be engine specific. This was from the iron small block (SBC/SBF) days.

 

[userfriendly]

I recall a study done years back that showed a 180 to be "ideal" from a wear perspective. A 160 was too cold and increased wear, while a 190 would result in ignition timing getting pulled, but having basically the same wear rate as the 180. Of course, this (timing getting pulled) would be engine specific. This was from the iron small block (SBC/SBF) days.

Right, but maybe not so much tming change if any from stock with E85. The knock sensors should control timing in any case, and with a hotter engine, less spark advance should be needed, and more advance with a cold engine.

 

[flash7210]

The cooler thermostat doesn't make the engine run cooler just causes it to take longer to warm up.

A 160 thermostat would be more effective if the radiator fans are set to turn on at 170

 

[flash7210]

Warmer engines are more efficient engines. Oil not getting up to temperature is not a good thing. If your oil temperatures are going above 250F then you might have a problem. Over 300F on the street is very problematic. You are doing no good to your engine, and oil, using a 160F thermostat. You engine oil should run consistently around 212F.

The OP didn't build this motor for efficiency. It's clearly setup for maximum HP.
Being that it's supercharged, keeping the cylinder heads as cool as possible would be important for achieving maximum HP.
A good crankcase evacuation system important too.

 

[OVERKILL]

Right, but maybe not so much tming change if any from stock with E85. The knock sensors should control timing in any case, and with a hotter engine, less spark advance should be needed, and more advance with a cold engine.

True, it was using 91 octane in the study I recall, and I believe the engine(s?) was/were naturally aspirated. My point being moreso that a 160 stat may be doing more harm than good if the results of this study extend to the OP's application, even if the 180 isn't ideal for this particular usage case, which I think you and I are in agreement on?