Is diesel dead?

[Roadtrek Adventuous RS1]

Originally Posted by Mfturner

I've been on steep enough grades that the v6 diesel rpm was in the mid 3000's to climb, so I can believe someone claiming 3800. The Winnebago Trend (Promaster) we rented was in the mid 5000's on similar hills. Riding in a van for an
extended climb in the mid 5000's is unpleasant, not to mention 8 mpg.

YES, it's very unpleasant...and the fuel economy sucks as well....

Even climbing mountains to 11,000 feet ... saving on the downgrade...the Sprinter averaged over 17 MPG.... and it wasn't breathing hard at all... I think it might have downshifted to 4 and still climbed up the mountain...it was last fall... don't remember exactly... but, we cruised up to the 11,000 peak around 50 to 55 MPH...and I wasn't flooring it...

There's a big difference between peak torque and redline...for example..in my Subaru..the most effective RPM is around 4,000..it can go a little more..but you won't necessarily go that much faster...

In driving the Sprinter normally..it shifts up between 1,800 to 2,500 RPMs and picks up speed quite briskly...

Only in situations where the engine is demanding the extra RPMs do I do that in my cars or the RV....

And manually shifting up is a complete waste as far as I'm concerned....I do use the engine braking on downgrades... very helpful.....

I wouldn't be driving my Sprinter across the USA if it only got 8 MPG....

[Mfturner]

I agree with all you say, but then I live in CO and long grades are between me and some of the places I want to go.

I can't honestly say this would be as important to me if I still lived in Atlanta. Maybe that's something I'm missing in this discussion, a large percentage of people in the US don't live near long grades like this.

[booster]

This is the torque/hp curve for the 6.0 gasser in our Chevy





It gets to the 325ft-lb about 2K rpm and is above that from there, so there is no need to climb in high rpm if you can get the transmission to stay in the right gear. The transmission programming is why the gas engine vehicles tend to scream going up steep grades, not necessarily because they need to. The programmers are almost certainly told to get the maximum power out of the drivetrain, and higher rpm will give that whether you need it or not. The diesels won't scream high rpm because they can't, so that problem doesn't exist. Having been next to Sprinters that are working hard, though, I can say they were substantially noisier than we were at the same output.



The other thing that the Chevy does is keep the torque converter unlocked for more power to the wheels, which is not really a good idea because you trade short term power for transmission heating. There is a thread on the topic on the forum.


When we could get the transmission to do it, with the converter locked, we could climb very well at 2500-2800 rpm. Unfortunately, it would only do that at higher speeds like 70mph+ so limited test on that. I have since gotten a programmer and changed the transmission settings for lockup and shiftpoints so that we will be able to climb at lower rpm and with the converter locked. We will be getting testing done in the mountains this year, I hope.


Put a small turbo or centrifugal blower on the torque curve shown, mainly just to compensate for altitude loss, and get the trans programming appropriate for an RV, and you would be able to climb anything while holding really good speed.


One thing that I will put in is that the lower the better on torque peak is not always a good idea when you start to get really low. You ideally want your torque peak to be at the rpm where need the most power to the wheels for the most amount of the time. Super low torque is good for a very heavy vehicle to be able to get it moving, but not so good for a moderate weight vehicle that is also concerned about holding speed on a long grade. My guess would be that the turbo setup on the Sprinter is designed to flatten the torque curve and 1400rpm to save the engine. It is quite easy with computer controlled fueling, especially with a diesel, to hold the torque constant from that point up the rpm range. I find it really interesting that the max torque range seems to run from 1400 to 3800 redline, as the very old "2500rpm rule" for turbo installs says that you get good boost for a 2500rpm range, you just need to pick the parts to decide where the 2500rpm is in your rpm range.

[Bud]

Originally Posted by booster

This is the torque/hp curve for the 6.0 gasser in our Chevy





It gets to the 325ft-lb about 2K rpm and is above that from there, so there is no need to climb in high rpm if you can get the transmission to stay in the right gear. The transmission programming is why the gas engine vehicles tend to scream going up steep grades, not necessarily because they need to. The programmers are almost certainly told to get the maximum power out of the drivetrain, and higher rpm will give that whether you need it or not. The diesels won't scream high rpm because they can't, so that problem doesn't exist. Having been next to Sprinters that are working hard, though, I can say they were substantially noisier than we were at the same output.



The other thing that the Chevy does is keep the torque converter unlocked for more power to the wheels, which is not really a good idea because you trade short term power for transmission heating. There is a thread on the topic on the forum.


When we could get the transmission to do it, with the converter locked, we could climb very well at 2500-2800 rpm. Unfortunately, it would only do that at higher speeds like 70mph+ so limited test on that. I have since gotten a programmer and changed the transmission settings for lockup and shiftpoints so that we will be able to climb at lower rpm and with the converter locked. We will be getting testing done in the mountains this year, I hope.


Put a small turbo or centrifugal blower on the torque curve shown, mainly just to compensate for altitude loss, and get the trans programming appropriate for an RV, and you would be able to climb anything while holding really good speed.


One thing that I will put in is that the lower the better on torque peak is not always a good idea when you start to get really low. You ideally want your torque peak to be at the rpm where need the most power to the wheels for the most amount of the time. Super low torque is good for a very heavy vehicle to be able to get it moving, but not so good for a moderate weight vehicle that is also concerned about holding speed on a long grade. My guess would be that the turbo setup on the Sprinter is designed to flatten the torque curve and 1400rpm to save the engine. It is quite easy with computer controlled fueling, especially with a diesel, to hold the torque constant from that point up the rpm range. I find it really interesting that the max torque range seems to run from 1400 to 3800 redline, as the very old "2500rpm rule" for turbo installs says that you get good boost for a 2500rpm range, you just need to pick the parts to decide where the 2500rpm is in your rpm range.

booster, it appears that our engines produce Sprinter max hp at less than 3000 rpm! If a Sprinter van was offered with the 'old' 6.0L Chevrolet engine, I would choose that and save money over the diesel, plus more benefits.

Bud

[Roadtrek Adventuous RS1]

Originally Posted by Mfturner

I agree with all you say, but then I live in CO and long grades are between me and some of the places I want to go.

I can't honestly say this would be as important to me if I still lived in Atlanta. Maybe that's something I'm missing in this discussion, a large percentage of people in the US don't live near long grades like this.

Yeah, I used to know someone who once told me... I live near the beach, where's it's always cool.... I don't need AIR CONDITIONING in my car..

Right.... yeah you do.... the theory that you might never leave the cool beach community is utter baloney.

Performance and power is efficiency... and having the diesel engine to move a vehicle with a gross weight of more 15,230 pounds needs a strong diesel engine....

There's a huge difference between an engine with "super high compression"... 18 to 1 vs. a gasoline engine that has maybe 9 or 10 to 1...

Diesel engines do twice the work of a typical gasoline engine... they have longer service intervals and maybe cost more when serviced ...but, they retain a much better resale than gasoline models.

[Roadtrek Adventuous RS1]

Originally Posted by Bud

booster, it appears that our engines produce Sprinter max hp at less than 3000 rpm! If a Sprinter van was offered with the 'old' 6.0L Chevrolet engine, I would choose that and save money over the diesel, plus more benefits.

Bud

Bud,

Actually, you're correct... the Mercedes 3 litre turbo diesel V6 develops 325 foot pounds of torque at 1,400 RPM... that's really significant..


You don't have to let it get to 2,500 or 3,000 RPMs for performance.

As for noise.. it's one of the quieter diesels.. listening to a gasoline engine RPMs at 4,500 is not quiet ..

Sure, a lot of older diesel engines are noisier …. but, my 2012 is not too bad.
I can easily carry on a normal conversation while the coach is underway.. even climbing to 11,000 feet.

[booster]

Originally Posted by Roadtrek Adventuous RS1

Yeah, I used to know someone who once told me... I live near the beach, where's it's always cool.... I don't need AIR CONDITIONING in my car..

Right.... yeah you do.... the theory that you might never leave the cool beach community is utter baloney.

Performance and power is efficiency... and having the diesel engine to move a vehicle with a gross weight of more 15,230 pounds needs a strong diesel engine....

There's a huge difference between an engine with "super high compression"... 18 to 1 vs. a gasoline engine that has maybe 9 or 10 to 1...

Diesel engines do twice the work of a typical gasoline engine... they have longer service intervals and maybe cost more when serviced ...but, they retain a much better resale than gasoline models.

The difference between 18 to 1 and 9 to one is just cylinder compression pressure, and a recoverable, mostly force. The difference just allows compression ignition.


The engine dyno or chassis dyno doesn't know the difference between diesel and gas, so the numbers it spits out are not specific to either.



Torque is force which determines if it will move.


Horsepower is work which determines how fast it will move at that torque.


A gasser making 325ft-lb of torque at2000rpm is doing exactly the same amount of work as a diesel at the same torque and rpm, and is very close to what the Chevy and Sprinter in these examples will do. They are both making right about at 123hp at that point.



So to say a 188hp diesel with 325ft-lb of torque can do twice the work of a 300hp gasser with 360ft-lb of torque is just not accurate, as hp is work and the gasser has nearly double the hp which is measured work. This is a bit off because they will get closer together as elevation increases because of a turbo on the diesel in this example, but if you were comparing to the 400ft-lb Ecoboost Ford, it would be directly comparable.

[Roadtrek Adventuous RS1]

Originally Posted by booster

The difference between 18 to 1 and 9 to one is just cylinder compression pressure, and a recoverable, mostly force. The difference just allows compression ignition.


The engine dyno or chassis dyno doesn't know the difference between diesel and gas, so the numbers it spits out are not specific to either.



Torque is force which determines if it will move.


Horsepower is work which determines how fast it will move at that torque.


A gasser making 325ft-lb of torque at2000rpm is doing exactly the same amount of work as a diesel at the same torque and rpm, and is very close to what the Chevy and Sprinter in these examples will do. They are both making right about at 123hp at that point.



So to say a 188hp diesel with 325ft-lb of torque can do twice the work of a 300hp gasser with 360ft-lb of torque is just not accurate, as hp is work and the gasser has nearly double the hp which is measured work. This is a bit off because they will get closer together as elevation increases because of a turbo on the diesel in this example, but if you were comparing to the 400ft-lb Ecoboost Ford, it would be directly comparable.

Remember that the 3.0 V6 is half the displacement of that 6.0 gas engine.... so, my point about efficiency and fuel economy is still valid...


My overall point about the diesel doing twice the work... generally is true if you consider that it's a much smaller powerplant and uses less fuel to do it.

[booster]

Originally Posted by Roadtrek Adventuous RS1

Remember that the 3.0 V6 is half the displacement of that 6.0 gas engine.... so, my point about efficiency and fuel economy is still valid...


My overall point about the diesel doing twice the work... generally is true if you consider that it's a much smaller powerplant and uses less fuel to do it.

But it is a turbo which can effectively double the output of either engine. I could build you a 3.0 gas engine that would perform like the 6.0 Chevy NA engine quite easily, on very low boost.



Also remember that the 6.0 has 300 hp so it will do way 60% more work than the turbo diesel at double the size, without a turbo. Put turbos on the 6.0 and you easily could get 500ft-lb of torque and 500hp, just look at the numbers for the 3.5L Ecoboost in an F150 470ft-lb torque and and 375hp. This is 45% more torque and double the hp, from an engine that is only 17% larger than the 3.0 diesel. Both are turbos so a more fair comparison.

[Roadtrek Adventuous RS1]

Originally Posted by booster

But it is a turbo which can effectively double the output of either engine. I could build you a 3.0 gas engine that would perform like the 6.0 Chevy NA engine quite easily, on very low boost.



Also remember that the 6.0 has 300 hp so it will do way 60% more work than the turbo diesel at double the size, without a turbo. Put turbos on the 6.0 and you easily could get 500ft-lb of torque and 500hp, just look at the numbers for the 3.5L Ecoboost in an F150 470ft-lb torque and and 375hp. This is 45% more torque and double the hp, from an engine that is only 17% larger than the 3.0 diesel. Both are turbos so a more fair comparison.

With the same fuel efficiency???

[cruising7388]

Originally Posted by Roadtrek Adventuous RS1

With the same fuel efficiency???

No, the Chev 6.0 for example won't have as high a fuel efficiency as the diesel. The Sprinter will give you around 18-19 mpg; the Chevy 6.0 will give you around 15-16 mpg.

But let's segue to what is actually relevant which is money out of pocket:


1. Diesel fuel use to save you money. Now it averages about 10% more than gas. In terms of dollars spent, just this factor significantly eats up the diesel mpg advantage.

2. The diesel initially cost you conservatively 5k more to buy than the gas alternative.

3. In general, service and repair costs for gas engines are substantially less than diesels and with Mercedes, you really get your chicken choked.

4. Service and repair for gassers is generally locally available. Depending on where you live, you may have to spend significant time and money to get to a Mercedes facility that will work on Sprinters.

Bottom line is that while there certainly is an mpg difference, in terms of money out of pocket, I think it's irrelevant.

[booster]

Originally Posted by cruising7388

No, the Chev 6.0 for example won't have as high a fuel efficiency as the diesel. The Sprinter will give you around 18-19 mpg; the Chevy 6.0 will give you around 15-16 mpg.

But let's segue to what is actually relevant which is money out of pocket:


1. Diesel fuel use to save you money. Now it averages about 10% more than gas. In terms of dollars spent, just this factor significantly eats up the diesel mpg advantage.

2. The diesel initially cost you conservatively 5k more to buy than the gas alternative.

3. In general, service and repair costs for gas engines are substantially less than diesels and with Mercedes, you really get your chicken choked.

4. Service and repair for gassers is generally locally available. Depending on where you live, you may have to spend significant time and money to get to a Mercedes facility that will work on Sprinters.

Bottom line is that while there certainly is an mpg difference, in terms of money out of pocket, I think it's irrelevant.

Yep, totally agree.


Besides that, nobody has stated the gasser get the same fuel economy, but they may in the near future, especially if you look at the % of heat energy of the fuel used. Diesel gets a headstart with fuel that contains more energy.


The point being made was that diesels don't do twice as much work, or have more grunt uphill because of the fact they are diesel and their torque and hp are somehow different than a gasser's torque and hp.


The other point is that when efficiency is equated to torque and hp per cubic liter, as long as you compare NA and turbo to themselves and not each other, gassers will make as much or more power than diesels.


For reference at the 3.0 torque peak of 325ft-lb at 1400rpm, the engine is making only 87hp, so you are not going to be going up a mountain very quickly at the torque peak.

[Roadtrek Adventuous RS1]

Originally Posted by cruising7388

No, the Chev 6.0 for example won't have as high a fuel efficiency as the diesel. The Sprinter will give you around 18-19 mpg; the Chevy 6.0 will give you around 15-16 mpg.

But let's segue to what is actually relevant which is money out of pocket:


1. Diesel fuel use to save you money. Now it averages about 10% more than gas. In terms of dollars spent, just this factor significantly eats up the diesel mpg advantage.

10 cents more per gallon..we get our fuel from Costco. By the way.. I've gotten as high as 21 and 22 on the flat open road with the Mercedes... depending on how fast I'm going...

Over time..and I'm talking long haul here...250,000 to 300,000 miles...fuel is the most expensive thing you can put in your vehicle.....

2. The diesel initially cost you conservatively 5k more to buy than the gas alternative.

Purchased this vehicle in May 2017 .. we're the second owners...but yes, I know they are generally more expensive.... BUT, you get this back when you sell...

3. In general, service and repair costs for gas engines are substantially less than diesels and with Mercedes, you really get your chicken choked.

Mercedes Benz dealership is extremely expensive... however, they know what they are doing.... last year..I had a problem with the emissions system... bottom line....they replaced the entire emissions system at no charge... under the emissions warranty...less than 8 years and 80,000 miles....... what independent garage would do that.... answer.. nobody.

4. Service and repair for gassers is generally locally available. Depending on where you live, you may have to spend significant time and money to get to a Mercedes facility that will work on Sprinters.

We live in Los Angeles...close to any Mercedes Benz dealership... but, on the road, you're correct....

I get my vehicle serviced before I leave on any long trip....

I'm going to try an independent Mercedes Benz Sprinter expert in the area soon....

It's all about the driving experience, I guess... maybe you have not driven a Sprinter...?
They definitely have a completely different feel from say a U-HAUL truck...

And, I've rented U-HAUL Chevy Express vans...it's a completely different driving experience..... Sorry..

I can't disagree with your assessment of the Mercedes Benz being more expensive..it's absolutely true... I never made any claim that it was cheaper....

All I said was..that the diesel engine is more efficient ..in terms of energy and performance for such a small powerplant...it's only 1/2 litre more in displacement than my FOUR cylinder Subaru Outback Limited that has a 2.5 litre engine....

Of course a 6 litre engine with a lot of displacement is going to have lots of power..
I wonder what the zero to 60 speed is on the Chevy Express??

One more thing to consider...if you look up diesel value on NADA..( National Dealers Automobile Association)... you'll discover that "mileage is NOT taken into account for value"...OK..why is this important... well... with all gasoline engine vehicles total mileage on the vehicle is definitely taken into account.....

SO...the total miles driven on a diesel ..are NOT as significant...and diesel engines are known for being extremely robust and frequently overbuilt.. going more than 500,000 miles...

I met someone who had the original engine with 800,000 kilometers.. that's 497,096 miles and the engine was still working fine... It's all about continued maintenance....

The "real test" of economy is...the total miles driven.... divided by the total cost....it matters a lot.

And I normally keep my vehicles for 15 to 20 years...


Bottom line is that while there certainly is an mpg difference, in terms of money out of pocket, I think it's irrelevant.

See my answers below.....

1. Diesel fuel use to save you money. Now it averages about 10% more than gas. In terms of dollars spent, just this factor significantly eats up the diesel mpg advantage.

10 cents more per gallon..we get our fuel from Costco. By the way.. I've gotten as high as 21 and 22 on the flat open road with the Mercedes... depending on how fast I'm going...

Over time..and I'm talking long haul here...250,000 to 300,000 miles...fuel is the most expensive thing you can put in your vehicle.....

2. The diesel initially cost you conservatively 5k more to buy than the gas alternative.

Purchased this vehicle in May 2017 .. we're the second owners...but yes, I know they are generally more expensive.... BUT, you get this back when you sell...

3. In general, service and repair costs for gas engines are substantially less than diesels and with Mercedes, you really get your chicken choked.

Mercedes Benz dealership is extremely expensive... however, they know what they are doing.... last year..I had a problem with the emissions system... bottom line....they replaced the entire emissions system at no charge... under the emissions warranty...less than 8 years and 80,000 miles....... what independent garage would do that.... answer.. nobody.

4. Service and repair for gassers is generally locally available. Depending on where you live, you may have to spend significant time and money to get to a Mercedes facility that will work on Sprinters.

We live in Los Angeles...close to any Mercedes Benz dealership... but, on the road, you're correct....

I get my vehicle serviced before I leave on any long trip....

I'm going to try an independent Mercedes Benz Sprinter expert in the area soon....

It's all about the driving experience, I guess... maybe you have not driven a Sprinter...?
They definitely have a completely different feel from say a U-HAUL truck...

And, I've rented U-HAUL Chevy Express vans...it's a completely different driving experience..... Sorry..

I can't disagree with your assessment of the Mercedes Benz being more expensive..it's absolutely true... I never made any claim that it was cheaper....

All I said was..that the diesel engine is more efficient ..in terms of energy and performance for such a small powerplant...it's only 1/2 litre more in displacement than my FOUR cylinder Subaru Outback Limited that has a 2.5 litre engine....

Of course a 6 litre engine with a lot of displacement is going to have lots of power..
I wonder what the zero to 60 speed is on the Chevy Express??

One more thing to consider...if you look up diesel value on NADA..( National Dealers Automobile Association)... you'll discover that "mileage is NOT taken into account for value"...OK..why is this important... well... with all gasoline engine vehicles total mileage on the vehicle is definitely taken into account.....

SO...the total miles driven on a diesel ..are NOT as significant...and diesel engines are known for being extremely robust and frequently overbuilt.. going more than 500,000 miles...

I met someone who had the original engine with 800,000 kilometers.. that's 497,096 miles and the engine was still working fine... It's all about continued maintenance....

The "real test" of economy is...the total miles driven.... divided by the total cost....it matters a lot.

And I normally keep my vehicles for 15 to 20 years

[Davydd]

You spend more money jockeying and idling waiting for an end pump to open up where diesel is dispensed in most service stations and subsequent cost of paper, soap, gloves, etc. in handling the filthy pump handles. That’s what I don’t like about diesel.

[VanFan]

Originally Posted by cruising7388

No, the Chev 6.0 for example won't have as high a fuel efficiency as the diesel. The Sprinter will give you around 18-19 mpg; the Chevy 6.0 will give you around 15-16 mpg.

But let's segue to what is actually relevant which is money out of pocket:


1. Diesel fuel use to save you money. Now it averages about 10% more than gas. In terms of dollars spent, just this factor significantly eats up the diesel mpg advantage.

2. The diesel initially cost you conservatively 5k more to buy than the gas alternative.

3. In general, service and repair costs for gas engines are substantially less than diesels and with Mercedes, you really get your chicken choked.

4. Service and repair for gassers is generally locally available. Depending on where you live, you may have to spend significant time and money to get to a Mercedes facility that will work on Sprinters.

Bottom line is that while there certainly is an mpg difference, in terms of money out of pocket, I think it's irrelevant.

Totally agree with this analysis. All four points, and especially the first one, are why I chose a gas ProMaster for my build. Per the manufacturer's websites, diesel Sprinters and Transits both cost about $11k more than the gas ProMaster with roof heights, lengths, and options as similar as possible. I whipped up a little spreadsheet to see how long it would take to recoup that $11k extra initial cost. Assuming my local average gas and diesel prices ($2.79 & $3.06) a 5 MPG fuel efficiency difference, and 15,000 miles per year, it would take about 11 years to get paid back. Of course, we don't usually put 15,000 on our van in a year, and the actual fuel efficiency difference is probably less than 5 MPG, so the real payback time is probably more than 11 years.

[avanti]

Yes. And, we'll see about the future of this extra "resale value" of diesel in light of the Volkswagen disaster and the constant drumbeat of emissions-related repair nightmare stories. And, warranty or no, many of them really are nightmares--especially for non-retired RV's on their precious 2-week vacations.

[Roadtrek Adventuous RS1]

Originally Posted by avanti

Yes. And, we'll see about the future of this extra "resale value" of diesel in light of the Volkswagen disaster and the constant drumbeat of emissions-related repair nightmare stories. And, warranty or no, many of them really are nightmares--especially for non-retired RV's on their precious 2-week vacations.

Look, I'm not saying that diesel is the ONLY way to go....they certainly have problems especially with emissions systems...and it's more complicated...

BUT, with an 11,030 pounds vehicle.... I chose the diesel....and by the way, the model I have...the 3500..with dual wheels... well, it doesn't come with a gasoline engine....

I think that's going to be introduced in 2019... we'll see how that fares when it gets introduced....

As per resale....it's NOT a VW....so, why bring that up.....?

[booster]

Originally Posted by Roadtrek Adventuous RS1

As per resale....it's NOT a VW....so, why bring that up.....?

From what we have heard lately, it is very possible nearly all the diesel manufacturers were doing the same thing, and the question still remains if diesels can meet standards and give good economy and power without cheating.

[avanti]

Originally Posted by Roadtrek Adventuous RS1

As per resale....it's NOT a VW....so, why bring that up.....?

Because most of the market isn't quite as sensitive to nuance as folks around here. That incident was the death knell of diesel in the US.


I hope you realize that I am a diesel owner, too. My Sprinter 3500's OM651 I4 engine with its 7-speed transmission is one of the most amazing powertrains that I have ever driven. I truly love it, when it is working. And, I have an excellent dealer that takes good care of me.

But, there is simply no denying that modern Sprinters are horribly unreliable vehicles, due almost entirely to the BlueTec system. I can no longer plan a trip without thinking about where I am going to head if I have yet another emissions failure. That is no way for an RV'r to live. And, the problem is not limited to Mercedes, since all the OEMs depend on basically the same tech. (The problem is exacerbated with MB, though, due to the limited dealer network and the expense of out-of-warranty repairs). Even if things get better, these stories are out there and they are bound to poison the market for diesel if there are any reasonable alternative, and, as we have discussed, the technology gap between gas and diesel has narrowed so dramatically in recent years that any remaining advantages of diesel are de minimis.

Moreover, I do not believe that things will get better. The fate of diesel in the US is clear to the OEMs. Mercedes didn't even bother to offer the I4 this year (despite its popularity) because they didn't see it as worth the cost of emissions certification. The R&D dollars are all going into EVs and gas-fueled hybrids.

Diesel is dead.

[Roadtrek Adventuous RS1]

Originally Posted by booster

From what we have heard lately, it is very possible nearly all the diesel manufacturers were doing the same thing, and the question still remains if diesels can meet standards and give good economy and power without cheating.

Are you just saying that or do you have proof?

YES, VW definitely cheated...and that was horrible....

MERCEDES used a completely different system for their vehicles....

I don't know how you can say this without any hard evidence...