Sprinter to replace V6 diesel with 4 cylinder

[Chance]

Various reports following Work Truck Week indicate Mercedes will replace 3.0L V6 with with two 2.0L inline-4 diesels next year — Model Year 2023.

Reports don’t specifically mention cutaway chassis used for Class C motorhomes, but new smaller engine with twin turbos has 20 more horsepower and 7 lb-ft greater torque than present V6.

Mercedes is also switching Sprinter to AWD, and 9-speed.

The 2.0L turbo gas engine remains standard on some applications.


https://rvbusiness.com/sprinter-swit...ew-awd-system/

https://www.caranddriver.com/news/a3...ngine-changes/

[DavidEM]

Even though I understand that turbos can make lots of hp from a small engine, I think that 2.0 liters is too small for a 10,000+ vehicle.

In my boating days, Tony Athens a very hands on owner of a marine diesel shop in California, said that he would want to keep the continuous hp produced from a diesel down to 30 hp per liter for decent life. I suspect the 2.0 turbo is putting out more than that at a steady 65 mph.

I think that the 3.5 liter diesel stays under 30 hp per liter at 65.

It will be interesting to see if the MH builders jump on the 2 liter band wagon.

David

[Bob Denman]

Smaller engines with more boost...
It CAN work very well, and I'm sure that the M.B. engineers have it figured out...
...but for delivery vehicle applications.
Motorhomes are a completely animal to tune for...

[DavidEM]

Originally Posted by Bob Denman

Smaller engines with more boost...
It CAN work very well, and I'm sure that the M.B. engineers have it figured out...
...but for delivery vehicle applications.
Motorhomes are a completely animal to tune for...

Exactly!! I also wonder if Mercedes will keep the 11,000 lb GVWR with the smaller engine. I suspect not and the bigger 25'+ Class Cs will have to find another chassis.

David

[Chance]

Originally Posted by DavidEM

Even though I understand that turbos can make lots of hp from a small engine, I think that 2.0 liters is too small for a 10,000+ vehicle.

In my boating days, Tony Athens a very hands on owner of a marine diesel shop in California, said that he would want to keep the continuous hp produced from a diesel down to 30 hp per liter for decent life. I suspect the 2.0 turbo is putting out more than that at a steady 65 mph.

I think that the 3.5 liter diesel stays under 30 hp per liter at 65.

It will be interesting to see if the MH builders jump on the 2 liter band wagon.

David

On the surface it sounds a bit much, but is it?

The reported torque of 332 lb-ft for 2 liter engine is equivalent to 1,100 lb-ft for a 6.7-liter engine at same BMEP (brake mean effective pressure), so not that much higher than torque limits Cummins and Ford are pushing already. Still, 170 lb-ft of torque per liter is no doubt high for commercial trucks, as seen when Ford and Cummins derate their 6.7L engines significantly when installed in larger vehicles.

Limiting power to 30 HP per liter makes little sense because it doesn’t take engine size into account. Smaller engines can and normally rev (spin) faster so will make more power per liter than otherwise similar engines. That rule is too broad to be of real value in my opinion.

Common Sprinter Class Cs at moderate highway speeds are probably in range of 100 HP while cruising on level roads. That would certainly exceed Athens’ 30 HP/liter rule of thumb, though it doesn’t work that way to start with.

[HMCSW]

Originally Posted by DavidEM

Even though I understand that turbos can make lots of hp from a small engine, I think that 2.0 liters is too small for a 10,000+ vehicle.

In my boating days, Tony Athens a very hands on owner of a marine diesel shop in California, said that he would want to keep the continuous hp produced from a diesel down to 30 hp per liter for decent life. I suspect the 2.0 turbo is putting out more than that at a steady 65 mph.

I think that the 3.5 liter diesel stays under 30 hp per liter at 65.

It will be interesting to see if the MH builders jump on the 2 liter band wagon.

David

tony is The Man… we too came from boating. Twin Cummins .. He was a super resource for us over the years. Both for upkeep and when we were looking for a new boat.

[DavidEM]

Tony was old school and expected well maintained diesels to go 10,000 hours or more before major overhaul. But I suspect that few if any Class C diesels ever go 10,000 hours.

If all you expect is your Class C to go 100,000 miles then that is just 2-3,000 hours and the 2 liter engine can probably make that.

I would much prefer the 3.5 liter diesel though.

David

[Chance]

Originally Posted by DavidEM

Tony was old school and expected well maintained diesels to go 10,000 hours or more before major overhaul. But I suspect that few if any Class C diesels ever go 10,000 hours.

If all you expect is your Class C to go 100,000 miles then that is just 2-3,000 hours and the 2 liter engine can probably make that.

I would much prefer the 3.5 liter diesel though.

David

About 4 or 5 years ago Mercedes introduced a 3L inline six diesel meant to replace V6 engines. I would guess that the inline six is too long to fit under Sprinter hood, and that Mercedes wouldn’t keep the V6 around if to power only the Sprinter. I don’t know for sure, but expect they didn’t have much choice.

Perhaps they feel the OM654 2.0L diesel, which has more power and torque than V6, will last long enough. In Europe the Ford Transit and Fiat Ducato have been relying on +/- 2.0L 4-cylinders for years, making the V6 Sprinter even higher in cost by comparison.

Personally, I think the inline six would be pretty cool if it fit.