What difference does 5w/30 make in the Hemi vs 5w20

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Aug 7, 2016
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New Hampshire
I was combing through the owners manual and found some discrepancy. There's a ton of baggage around 5w20/30 affecting the way the MDS system works and I've even been told that it'll throw a code if it senses an oil outside 20wt parameters as the oil pressure is used to run the valve shutoff for the MDS system. As it is written in the manual
Engine Oil – 5.7L EngineWe recommend you use API Certified SAE 5W-20 Engine Oil, meeting the requirements of FCA Material Standard MS-6395 such as MOPAR, Pennzoil, and Shell Helix. Refer to your engine oil filler cap for correct SAE grade.
Engine Oil – 5.7L Engine 2500/3500 trucks operating under a gross combined weight rating greater than 14,000 lbs/(6,350 kg.)We recommend you use API Certified SAE 5W-30 Engine Oil, meeting the requirements of FCA Material Standard MS-6395 such as MOPAR, Pennzoil, Shell Helix or equivalent. Refer to your engine oil filler cap for correct SAE grade.
My vehicle is a 2019 1500 classic 4x4 with the 8-speed automatic for what its worth.
Do they program the motor for the 2500/3500 chassis trucks differently to operate with 5w30?
What is leading to this discrepancy and am I wrong to believe that this eludes to 5w30 being okay to operate in my 1500 without the motor knowing any different.
 
Do they program the motor for the 2500/3500 chassis trucks differently to operate with 5w30?

No, or at least I highly doubt it. A few cst's of VII's will not make a difference on a 'VDM' or VCT. But I'd just run a good syn 5W-20 and worry about more pressing things in life. You live in NH, not Death Valley and I'm guessing you have a high volume oil sump and oil cooler....
 
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No, or at least I highly doubt it. A few cst's of VII's will not make a difference on a 'VDM' or VCT. But I'd just run a good syn 5W-20 and worry about more pressing things in life. You live in NH, not Death Valley and I'm guessing you have a high volume oil sump and oil cooler....
So my commute is the Kancamagus Highway so my commute has a 2000+ foot elevation gain in about 15 miles hence why I'm feeling like having a heavier oil in the sump would be better when I'm doing that several days a week during the summer at 80-100+ degrees. I'm not 100% sure if my motor has a dedicated oil cooler line either and it takes 7qts
 
The difference between some 5w20 and 5w30 is around 15-20% thicker certainly no issues with a regular 5w30 such as PP.
 
HPL 5W20 vs. 5W30

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How long does it take your HEMI's oil temperature to pass 100F? In my climate, it is less than 5 minutes of driving.
 
My point was: the greatest differences in viscosity will be during the warm-up period. Depending on how long it takes for your engine (and environment to warm up), the differences between the two could be negligible.
Sorry wrong response...
 
I was combing through the owners manual and found some discrepancy. There's a ton of baggage around 5w20/30 affecting the way the MDS system works and I've even been told that it'll throw a code if it senses an oil outside 20wt parameters as the oil pressure is used to run the valve shutoff for the MDS system. As it is written in the manual
Engine Oil – 5.7L EngineWe recommend you use API Certified SAE 5W-20 Engine Oil, meeting the requirements of FCA Material Standard MS-6395 such as MOPAR, Pennzoil, and Shell Helix. Refer to your engine oil filler cap for correct SAE grade.
Engine Oil – 5.7L Engine 2500/3500 trucks operating under a gross combined weight rating greater than 14,000 lbs/(6,350 kg.)We recommend you use API Certified SAE 5W-30 Engine Oil, meeting the requirements of FCA Material Standard MS-6395 such as MOPAR, Pennzoil, Shell Helix or equivalent. Refer to your engine oil filler cap for correct SAE grade.
My vehicle is a 2019 1500 classic 4x4 with the 8-speed automatic for what its worth.
Do they program the motor for the 2500/3500 chassis trucks differently to operate with 5w30?
What is leading to this discrepancy and am I wrong to believe that this eludes to 5w30 being okay to operate in my 1500 without the motor knowing any different.
The code is triggered by inferred viscosity derived from oil temp and oil pressure, an xW-30 won't trigger it, you have to go pretty heavy to get it.

That said, I run 0W-20 in our 5.7L without reservation, it has a factory oil cooler and seems to do a good job of keeping the temps in check, even while towing.
 
So my commute is the Kancamagus Highway so my commute has a 2000+ foot elevation gain in about 15 miles hence why I'm feeling like having a heavier oil in the sump would be better when I'm doing that several days a week during the summer at 80-100+ degrees. I'm not 100% sure if my motor has a dedicated oil cooler line either and it takes 7qts

Someone did a long term oil temp study and found their oil temps vary about 10F in warmer months. It doesn't make much of a difference if you have a good cooling system and large oil sump. My brother lives in NH and it's rarely close to 100F....
 
The code is triggered by inferred viscosity derived from oil temp and oil pressure, an xW-30 won't trigger it, you have to go pretty heavy to get it.

That said, I run 0W-20 in our 5.7L without reservation, it has a factory oil cooler and seems to do a good job of keeping the temps in check, even while towing.
Once the vehicle reaches operating temp, the dash shows coolant and oil staying around 208-225F and 222-228F respectively during my commute in summer weather and 198-210F and 200-212F during winter months. Like I'd said, lots of high-revving with steep incline during the commute. My combo has been PUP 5w20 with a bottle of Lubegard Bio-Tech and a Fram XG2 with ~5k OCI, changing the filter every other oil change. I want to keep the Moly a little high to be kind to my cam but I also know that SOPUS runs a little thin within grade and my point here is if starting with an xw30 shears down into xw20 territory, it makes me feel better than starting in xw20 territory. Just looking to avoid throwing a code if I choose to switch. I'm about 15k miles from being out of warranty so if switching to a 5w30 isn't going to make the MDS system get angry and/or throw a code I plan to do so.
 
Someone did a long term oil temp study and found their oil temps vary about 10F in warmer months. It doesn't make much of a difference if you have a good cooling system and large oil sump. My brother lives in NH and it's rarely close to 100F....
Well up here in the WMNF we've been in the 90's during the daytime for almost 3 weeks. That coupled with the steep inclines means higher revving and more heat, hence my interest in an oil that won't shear below the "recommended" xw20wt oil
 
Once the vehicle reaches operating temp, the dash shows coolant and oil staying around 208-225F and 222-228F respectively during my commute in summer weather and 198-210F and 200-212F during winter months. Like I'd said, lots of high-revving with steep incline during the commute. My combo has been PUP 5w20 with a bottle of Lubegard Bio-Tech and a Fram XG2 with ~5k OCI, changing the filter every other oil change. I want to keep the Moly a little high to be kind to my cam but I also know that SOPUS runs a little thin within grade and my point here is if starting with an xw30 shears down into xw20 territory, it makes me feel better than starting in xw20 territory. Just looking to avoid throwing a code if I choose to switch. I'm about 15k miles from being out of warranty so if switching to a 5w30 isn't going to make the MDS system get angry and/or throw a code I plan to do so.
It's a roller cam, moly isn't going to be any more "kind" to it ;) Either the rollers roll, or they don't, and if they don't, you have bigger problems.

FM chemistry (moly is a type of FM) may have an impact on how abrupt MDS feels coming on and off, but that's just speculation. Moly is an excellent friction modifier, but there are several others too, like tungsten and titanium compounds. The best results may also be achieved by blending different FM chemistries (like HPL does) but this is obviously more expensive.

Only way for you to know if the xW-30 is going to shear is to try it and then get it tested. Most viscosity loss is actually driven by fuel, not shear, it's just that most UOA's posted here are from Blackstone, that doesn't properly measure fuel.

We had a member, Clevy, who ran 0W-40 in his Charger R/T and he was only able to trigger the viscosity code when it was -40C where he lived out West.

Keep in mind, the MDS system between the 6.4L that specs 0W-40 and the 5.7L, which specs 5W-20 (and now 0W-20) is the same. Parts are all the same. The ECM in the 5.7L is just programmed to infer viscosity differently than the 6.4L is and this could be entirely related to emissions compliance "nannying".
 
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