Driving in Tow/Haul mode all the time

Weekiman · Sep 14, 2026

The wife has a 2023 Classic Hemi. She saw something on Tik Tic about driving in Tow/Haul mode which makes sense to me. It keeps it running on 8 cylinders all the time. It also limits the transmission shifts. I drive a 93 Cummins that's already too new of a vehicle for me. I don't like Democrat regulations. That's why we bought a Classic to avoid as many as possible. Supposedly this helps your vehicle last longer, but sounds like it might hurt gas mileage.

Wild one · Sep 14, 2026

Weekiman said:
The wife has a 2023 Classic Hemi. She saw something on Tik Tic about driving in Tow/Haul mode which makes sense to me. It keeps it running on 8 cylinders all the time. It also limits the transmission shifts. I drive a 93 Cummins that's already too new of a vehicle for me. I don't like Democrat regulations. That's why we bought a Classic to avoid as many as possible. Supposedly this helps your vehicle last longer, but sounds like it might hurt gas mileage.

There is "No" proof driving with tow/haul engaged does anything for promoting longevity. The lifters actually get more oil when the engine is in mds mode/aka 4 cylinder mode,as they use oil pressure to put the engine into 4 cylinder mode. Alot of times it's the Non-MDS lifters that fail,not the MDS lifters.Tell your wife to stay off Tik Toc :Big Laugh:

If you want it to last,tell her to drive it like it's her dads truck and she's 16 again.The Hemi is an engine that survives better if it's drove on the aggressive side,babying them does nothing to keep the engine alive,so tell her to use the skinny pedal like she's a kid again
Spend 16 minutes and watch this video about how the MDS system works.

Is MDS Damaging Your HEMI? The Answer May Surprise You!

I feel like MDS has been unfairly made the culprit for the lifter failures we see on Gen 3 Hemi engines. In this video I explain exactly how the system works...

www.youtube.com

Weekiman · Sep 14, 2026

Wild one said:
There is "No" proof driving with tow/haul engaged does anything for promoting longevity. The lifters actually get more oil when the engine is in mds mode/aka 4 cylinder mode,as they use oil pressure to put the engine into 4 cylinder mode. Alot of times it's the Non-MDS lifters that fail,not the MDS lifters.Tell your wife to stay off Tik Toc
If you want it to last,tell her to drive it like it's her dads truck and she's 16 again.The Hemi is an engine that survives better if it's drove on the aggressive side,babying them does nothing to keep the engine alive,so tell her to use the skinny pedal like she's a kid again
Spend 16 minutes and watch this video about how the MDS system works.

Is MDS Damaging Your HEMI? The Answer May Surprise You!

I feel like MDS has been unfairly made the culprit for the lifter failures we see on Gen 3 Hemi engines. In this video I explain exactly how the system works...

www.youtube.com

She's driving right now and laughing as I read this to her. I'm always telling her to settle down even though I own a drag car and love speed. I just don't want to kill this over complicated Democrat spacecraft. I'll sent this video to her. Thanks!

joesstripclub · Sep 14, 2026

I think there are some years it works, but for most newer trucks tow/haul does not shut off MDS. You can use the gear selector to select 8 and that will definitely shut off MDS if you want to. I agree though that MDS is not the problem.

Wild one · Sep 14, 2026

Weekiman said:
She's driving right now and laughing as I read this to her. I'm always telling her to settle down even though I own a drag car and love speed. I just don't want to kill this over complicated Democrat spacecraft. I'll sent this video to her. Thanks!

The ones that have issues with the cam and lifters are the ones drove by Grandma Jones,the ones drove by her 16 year old Grandson who has 2 positions to the gas pedal "idle and wide open" live forever :Big Laugh:

Wild one · Sep 14, 2026

Weekiman said:
She's driving right now and laughing as I read this to her. I'm always telling her to settle down even though I own a drag car and love speed. I just don't want to kill this over complicated Democrat spacecraft. I'll sent this video to her. Thanks!

The Multi-Displacement System (MDS) does not inherently destroy your engine through normal driving, but the real surprise is that simply turning off the software without changing the mechanical lifters can actually cause the cam and lifter damage people are trying to prevent. [1, 2]

How MDS Works

- The system shuts down four cylinders (1, 4, 6, and 7) during light-load driving to boost fuel economy by 8% to 15%.
- Engine oil pressure controls special locking pins inside the MDS lifters to collapse them and stop the valves from opening.
- Active switching itself is generally smooth and not the root cause of mechanical failures. [1, 2, 3]

The Real Danger: Idling and Partial Deletes

- Extended Idling: During long periods of idling, MDS solenoids stay closed, which reduces optimal oil delivery and lubrication to the lifter rollers. [1, 2]
- Tuning It Off Incorrectly: If you use a tuner to turn off MDS via software without physically replacing the MDS lifters, the oil flow remains restricted, starving the gallery and leading to premature camshaft failure. [1, 2]
- Proper Deletion: A true MDS delete requires removing the solenoids, installing standard non-MDS lifters, and replacing the camshaft

Burla · Sep 14, 2026

I drove in tow haul for the first 7 years because I was avoiding low rpm shudder in 5 speed RFE, until I changed oil to c+ and no more shudder. Not an option for 8 speed or even needed in 8 speed. Point being, 7 years tow haul every trip no issues, still no issues year 16 in general. Tow haul might not help anything (except low rpm RFE shudder), but it surely don't hurt anything either. For an RFE it is very much an upgrade because of low rpm's not found in 8 speeds.

.

.

HEMIMANN · Sep 14, 2026

I use the tuner (Diablosport Edge) tow mode, but don't use their tow-non MDS mode.

However, since I have the 66RFE trans, I restrict gears to 4th, which is 1:1 From a lifetime of gearing, this 'feels' right for engine rpm and a marginal transmission pulling 7,000 lbs load.

Unsure if restricting gearshift to 4th turns off MDS or what, but I'd rather have the engine working in spark-ignited engine rpm peak torque range than lugging and constant shifting from low rpm in diesel torque range. Engine @ the higher peak torque rpm is splashing more oil on the cam too.

Wild one · Sep 14, 2026

HEMIMANN said:
I use the tuner (Diablosport Edge) tow mode, but don't use their tow-non MDS mode.

However, since I have the 66RFE trans, I restrict gears to 4th, which is 1:1 From a lifetime of gearing, this 'feels' right for engine rpm and a marginal transmission pulling 7,000 lbs load.

Unsure if restricting gearshift to 4th turns off MDS or what, but I'd rather have the engine working in spark-ignited engine rpm peak torque range than lugging and constant shifting from low rpm in diesel torque range. Engine @ the higher peak torque rpm is splashing more oil on the cam too.

If you're keeping the rpms up around 2500+ then it's getting lots of cranksplash Brian

HEMIMANN · Sep 14, 2026

Wild one said:
If you're keeping the rpms up around 2500+ then it's getting lots of cranksplash Brian

Um, did I not say this? Or did I type in incomprehensible gibberish (again)?

Wild one · Sep 14, 2026

HEMIMANN said:
Um, did I not say this? Or did I type in incomprehensible gibberish (again)?

But you left out the rpm numbers

jc56berg · Sep 14, 2026

I ran across a You Tube video titled "The secret Ram function only 1% of owners know". Basically, its saying even when not towing or hauling to use this function. I don't tow anymore and only haul groceries and my cat once in a while. Says it keeps all 8 cylinders going and lifters lubed up but you don't ever go into overdrive. I have never used this option. I have read on several threads about this and including the Y/T video and @Wild one the link you put up. Long story short. To me Y/T can be helpful, but I wouldn't call it scripture every time. The video is 17 minutes long then after it is a video about tow/haul and your tranny. Whats a guy to do?

Wild one · Sep 14, 2026

jc56berg said:
I ran across a You Tube video titled "The secret Ram function only 1% of owners know". Basically, its saying even when not towing or hauling to use this function. I don't tow anymore and only haul groceries and my cat once in a while. Says it keeps all 8 cylinders going and lifters lubed up but you don't ever go into overdrive. I have never used this option. I have read on several threads about this and including the Y/T video and @Wild one the link you put up. Long story short. To me Y/T can be helpful, but I wouldn't call it scripture every time. The video is 17 minutes long then after it is a video about tow/haul and your tranny. Whats a guy to do?

Anybody telling you it won't go into the overdrive gears when not in mds mode is full of it,so take that video with a big grain of salt

Run it which ever way you want,it's your truck

Hell my truck didn't even have the mds solenoid wiring left in it,by the time i was done swapping in a non-mds cam,switching the solenoids out for the mopar plugs and installing all new OEM non-mds lifters,and it still went into 8th

Dan Topp · Sep 15, 2026

5 tons total today tow haul

55mph for 7 miles and 120 trans temp. Best mod I’ve done is the trans heater bypass.

Rlaf75 · Sep 15, 2026

Like others have said, its not so much the MDS causing lifter issues. Excessive idling and extended oil change intervals are the big culprits. I do use the gear limiter everytime I put the truck in gear because like you, I hate the EPA restrictions. I dont even have e-torque

jc56berg · Sep 15, 2026

Wild one said:
Anybody telling you it won't go into the overdrive gears when not in mds mode is full of it,so take that video with a big grain of salt Run it which ever way you want,it's your truck Hell my truck didn't even have the mds solenoid wiring left in it,by the time i was done swapping in a non-mds cam,switching the solenoids out for the mopar plugs and installing all new OEM non-mds lifters,and it still went into 8th

I'm going to drive it like I have been driving it. I'm not about to go experimenting from a Y/T video. I've had no problems since I've had it. I don't tow or haul just drive. Like I said just because its on Y/T doesn't mean its gospel. I did do the video on the seat belt "ding ding ding" omit when its not buckled. I'll take my chances on a 3 block drive in the neighborhood to my buddy's house for red meat and MNF. Don't want to walk home at 11 or 12 at night. Oh, liked your video on it.

jc56berg · Sep 15, 2026

Wild one said:
There is "No" proof driving with tow/haul engaged does anything for promoting longevity. The lifters actually get more oil when the engine is in mds mode/aka 4 cylinder mode,as they use oil pressure to put the engine into 4 cylinder mode. Alot of times it's the Non-MDS lifters that fail,not the MDS lifters.Tell your wife to stay off Tik Toc
If you want it to last,tell her to drive it like it's her dads truck and she's 16 again.The Hemi is an engine that survives better if it's drove on the aggressive side,babying them does nothing to keep the engine alive,so tell her to use the skinny pedal like she's a kid again
Spend 16 minutes and watch this video about how the MDS system works.

Is MDS Damaging Your HEMI? The Answer May Surprise You!

I feel like MDS has been unfairly made the culprit for the lifter failures we see on Gen 3 Hemi engines. In this video I explain exactly how the system works...

www.youtube.com

Really like this video. Third time I've watched it.

Burla · Sep 18, 2026

This SECRET RAM Function Only 1% of Owners Know

There's a button on your dash you press maybe twice a year, and using it right takes the most expensive repair on your HEMI off the table. It costs you nothi...

youtu.be

Driving in Tow/Haul mode all the time

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Similar threads

Forum statistics