I was thinking about going to a 5w-40 vs 0w-40 in my ram because I live in the land of scorched earth. When I tow it is from on thousand feet above see level to almost 8 thousand feet in less than 2 hours and things get pretty hot. There are no signs of issues but was thinking this may be an extra level of protection in this environment. I wouldn't imagine such a small increase would affect the VVT but would rather get some input before I gave it a shot.

Thanks

I currently drive a diesel Ram but have had 5.7 an 6.4 gas Rams. One of the first mods was always a lower temp thermostat. I live in South Louisiana. No need here to run those engines at that temp. Just want to keep the engine/tranny cool.

5/40 & 0/40 are the same viscosity at operating temperature, so no difference ,,,only difference is at cold start up,,,, I run 5/50 Lucas in my 2020 T/A 392 Challenger because I am in Southeast Texas. no problems, the Lucas label even says made for the Gen3 Hemi

Not an issue for this board, but just don't do it in a Honda. My kids Accord has a 2.4 with VVT and the prior owner used the wrong oil weight. The VVT didn't work till I put in the correct oil weight and then it ran like a watch.

Personally I would follow the manufacturer's recommendations. I read a detailed article in a law enforcement magazine written by a fleet manager of a very large agency and he discussed this very topic and how many agencies have learned the hard way not to use anything but manufacturer's recommendation for these engines, as they are very sensitive to oil weight.

I know many will argue this. I'm just telling you what I've read and my opinion.

When my 16 5.7 Ram went out of warranty I switched from 5w20 to 5w30. Next oil change I'm going to try 10w30. Truck has 82k on it & no problems in 12k with the change. I change my oil ever 5k. I live in Monroe NC & when I've done cold & hot oil changes on my truck it's like water running out of the pan. I also up graded the filter from Mopar to Wix 51372. I also change my stats in everything to 190*

There isn't enough difference in 0w40 vs 5w40 to lose sleep over

Any engine with VVT is basically using the oil as a hydraulic fluid to operate the VVT and motor oil is NOT a hydraulic fluid. That being said I would be careful about straying to far away from OEM specs.

Actually there is reasons to run them at those temps, for one it keeps water out of the oil better and water is a direct chemical byproduct of burning gasoline. Also helps MPG a tiny bit.

Yup, he's not gonna notice any difference in Mesa Arizona this time of year.

It is hot start up even at 5am every morning! Speaking of heat, how hot is too hot for these synthetics?

Like I said I am in the heat also, I went with 5/50 lucas that is made for the late model Hemi

I was told years ago that all petroleum based motor oil and ATF tranny fluid oils started deteriorating around 275 F and was dead above 325 F. . The guy that told me that was commercial airline pilot and A& P mechanic, he said that all the synthetic oils back then in late 1980 started failing around 525 F temps
My airplane had a oil cooler thermostat that tried to keep the oil temps above 160 F, and it did that well My airplane had straight 50 WT oil in it when i bought it and I switch to Mobil AV1 which was a pure synthetic lubricant that didn't carry contaminants worth a hoot, it sludge that motor up badly in a little over 300 hours
I then switch to Aero Shell20W 50 WT petroleum base oil and never had any issue with that oil other than it cleaning and washing the sludge off the inside of the motor and partially clogging up the oil cooler in the summer of 1998 I would change the oil and the FAA approved extra long non stock oil filter around 50 hours or less running time. I would cut the oil filter open and inspect it along with sending in an oil sample for testing on every oil change, I did NOT want that motor stopping or failing in flight
I did have one partial engine failure when a exhaust valve failed letting a piece of it go through the passenger side rear cylinder after leveling off and starting to adjust the fuel mixture for straight and level flight at 8500 Ft above mean sea level, that took me a little while, probably around 90 seconds, to decide what to do, go back, go home or go to the nearest airport to land, I turned back around 30 miles to land at Prescott, AZ Airport that had a lot of repair facilities on the airport due to them having a Embree Riddle (SP?) Aeronautical training facility their
The pucker factor was very high

All you need to worry about is that the oil temp hits 212 or higher to evaporate the water out of the oil! All the other mumbo jumbo is so the MFG. can hit their quotas. 190 stat will do that down here in the south!!

As far as t-stats I'm still on the fence as to whether to go with a 190. One part says cooler/more power but the other part worries about complete burn off.

I changed to lower thermostat and it didn't do anything for the high side.
Stock system operated from 205 - 230 (factory fan doesn't turn on until 225)
I replaced with the 193 thermostat, it then operated 195 - 230 it's hot here all the time.
I then reprogrammed the fan to come on at 215, so car now operates 195-220.

So unless you live in a cooler area, don't bother, lower thermostat won't do much.

I put a 185 tstat on my 2020 T/A 392, its hot down here in Southeast Tx, it runs 185 all the time in the summer. with the ac on the fans come on & keep it 185, at road speeds it runs 185, in the colder weather not using the ac it will get up to 220 but soon as I get up to speed it cools right back down to 185

I'm in Florida like you.