EPA flexing their muscles

oilhammer said:

Remember that one year an NAIAS where MB had that diesel hybrid E-class displayed? Wonder what became of that. Looked to be the OM651 engine coupled to a Bosch hybrid system. Probably pricey, but probably impressive fuel economy on both city and highway driving.

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The original concept Atlas was also setup as a diesel hybrid.

oilhammer said:

Discussing that in another thread, and it has been tried back in the '80s and early '90s. I think it is best suited for yard lot transfer trucks, as OTR trucks typically cruise at a higher speed and the modern transmissions they use (mostly automated manuals) are pretty efficient at keeping the engine in the sweet spot.

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One of our trucking firms came and gave us a demo on chemical handling the other day but the questions turned to talking about the tractor. They're using all Freight Liners with automatics. Said it was like driving a laz-y-boy now. All the bells and whistles to keep them in the lane and adaptive cruise. Said that they can get up to 11 mpg fully loaded at highway cruising, which is governed at 68 mph.

kjclow said:

One of our trucking firms came and gave us a demo on chemical handling the other day but the questions turned to talking about the tractor. They're using all Freight Liners with automatics. Said it was like driving a laz-y-boy now. All the bells and whistles to keep them in the lane and adaptive cruise. Said that they can get up to 11 mpg fully loaded at highway cruising, which is governed at 68 mph.

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There's a lot of light duty trucks that can't even do 11 MPG while towing within their much lesser capacity.

11 MPG out of a massive semi that can haul 80,000+ lbs is nuts.

There have been a lot of good things to say about Daimler/Detroit's DT12 automated transmissions. I think that has a lot to do with improved fuel economy of the big Freightliners. Volvo's iShift has been pretty successful as well.

IndigoBlueWagon said:

I still think it would be great to have a diesel engine hybrid with a Chevy Volt-like propulsion system, perhaps with even smaller batteries than the Volt. The engine could run at peak efficiency and let the electric motors provide motive power.

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Diesel engine + all of its associated emission control systems + hybrid system components = too much money.

Or, you recognise that since the way the vehicle drives no longer depends much on the shape of the torque curve ... you take the gasoline engine and fiddle with the cam timing to obtain Atkinson-cycle operation, which results in little low-end torque but it doesn't matter because the electric motor operates best there. See: Toyota Hybrid Synergy Drive.

There are limits to the concept of "run the engine at peak efficiency and let the electric motors provide motive power". The problem with that, is that the power available close to the engine's sweet spot of highest-efficiency operation rarely coincides with road load, with the result that the engine will always be charging or discharging the battery, so you get charge/discharge losses. That's why the Toyota Prius sends most of the engine torque through the mechanical torque path, and it varies engine output to match road load up to certain limits. That's why a Volt is capable of mechanically coupling the engine to the wheels, and it varies engine output to match road load up to certain limits.

It's worth operating the engine "off design" sacrificing a few points of efficiency if it allows NOT having the charge/discharge losses.

The way the Priuses and Volts and Ford hybrids all work when they are in combustion-engine mode, is that they try to operate the engine within its best-efficiency regime, matching road load, driving the wheels mechanically, whenever they can. If there is so little demand that engine efficiency would be poor, and the battery is sufficiently charged, they shut the engine down and operate electric-only. If the battery charge drops too low then they start the engine and run it under load to recharge it - the idea being that the total of the road load and the recharging load gets it back into its best-efficiency regime.

It is quite a sophisticated optimisation strategy ... But the driver still plays into it. I've had a Ford Fusion hybrid as a rental car, and the trick was to play along with the state of charge of the batteries, taking advantage of terrain where possible, the idea being to help it to run the engine as little as possible but IF it was running, keep it under load.

Matt-98AHU said:

11 MPG out of a massive semi that can haul 80,000+ lbs is nuts.

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I haul a skid steer for work here and there, 26,000 pound combined vehicle weight, and that gets 9-10 MPG depending on terrain and speed.

11 MPG for a loaded semi is quite impressive!

Since EPA is in this thread, has anyone ever wondered why EPA does not mandate that cruisers that are lurking in speed traps, parked at traffic stops, guarding certain churches during days of worship, full time and attention in wrecks, TURN OFF THEIR ENGINES and not keep the engine on idle?

whizznbyu said:

Since EPA is in this thread, has anyone ever wondered why EPA does not mandate that cruisers that are lurking in speed traps, parked at traffic stops, guarding certain churches during days of worship, full time and attention in wrecks, TURN OFF THEIR ENGINES and not keep the engine on idle?

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Well you could expand that to include any and all gov't agencies. Does the Secret Service really need to use Suburbans with only four people in each on, or could they use a G-van with 10 people inside instead?

I mean that is a never ending hole right there.

Go to the White house. There are COUNTLESS Suburbans parked with motors running a trail of airconditioning condensate that goes to the drain.

whizznbyu said:

Since EPA is in this thread, has anyone ever wondered why EPA does not mandate that cruisers that are lurking in speed traps, parked at traffic stops, guarding certain churches during days of worship, full time and attention in wrecks, TURN OFF THEIR ENGINES and not keep the engine on idle?

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Fellow governmental agencies get a pass from regulations, duh

And then their gas engine suffers from a cracked exhaust manifold and the occupants suffer from CO poisoning... *cough*FORD EXPLORER*COUGH*

Of course, CO poisoning could be avoided... with a diesel

Matt-98AHU said:

Fellow governmental agencies get a pass from regulations, duh
And then their gas engine suffers from a cracked exhaust manifold and the occupants suffer from CO poisoning... *cough*FORD EXPLORER*COUGH*
Of course, CO poisoning could be avoided... with a diesel

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The "Beast" has a diesel.

Interesting. I'd love to know more about the power plant in the presidential limo. I'd guess it might be a tweaked Duramax. But maybe it's a pure mechanical injection setup to eliminate any kind of electronic interference?

That has been discussed before, and it has been published that it is a gasoline engine... however someone I know and trust has actually been present when it drove by and he swears it is a diesel.

It has been speculated that the current and previous versions rode on a GM Topkick (medium duty truck) chassis, with a Cadillac "skin" over it that appears to be a morphed enlarged version of some existing model, sort of like an Escalade sedan.

Standard engines in those trucks are the 8.1L Vortec V8 or the 6.6L Duramax V8. But who knows.

https://www.livetradingnews.com/facts-new-2017-presidents-limo-aka-beast-27359.html#.XbA-ZG5FwYw

http://etcgreen.com/cadillac-one-presidential-limo-runs-biodiesel/

https://www.aallinlimo.com/blog/crazy-facts-about-the-presidential-limo/

turbobrick240 said:

Interesting. I'd love to know more about the power plant in the presidential limo. I'd guess it might be a tweaked Duramax. But maybe it's a pure mechanical injection setup to eliminate any kind of electronic interference?

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I remember when they did an update to 'The Beast' under Obama, I read that they were using the old GM 6.5L IDI turbo diesel...

Not a spectacularly powerful, efficient or clean engine, but being purely mechanical, it'll withstand an EMP blast and keep driving... So there's that.

Matt-98AHU said:

I remember when they did an update to 'The Beast' under Obama, I read that they were using the old GM 6.5L IDI turbo diesel...
Not a spectacularly powerful, efficient or clean engine, but being purely mechanical, it'll withstand an EMP blast and keep driving... So there's that.

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That makes sense to me. The thing really doesn't need to be very fast, just dead reliable. A p-pump Cummins would be better imo, but it's GM based so....

turbobrick240 said:

That makes sense to me. The thing really doesn't need to be very fast, just dead reliable. A p-pump Cummins would be better imo, but it's GM based so....

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The military is also pretty well familiar with it since it powered a whole lotta military Humvees. Going with what they know.

Matt-98AHU said:

I remember when they did an update to 'The Beast' under Obama, I read that they were using the old GM 6.5L IDI turbo diesel...

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It was never officially stated, but it sure sounded like a 6.5 to me. I imagine it had a DPF they just replaced often.

I know a fair bit about "The Beast" and there is a lot that none of us will ever know b/c it is quite classified by the Secret Service.

Public knowledge:
It is a diesel, currently based on a Kodiak truck chassis.
It might LOOK like a Cadillac limo, but that is where the similarity ends.
The tires are bulletproof runflat tires with special interior armor that prevents failure and allows continued operation without air.
There is a substantial amount of armor on it - how much and where is VERY classified, but it is expected to survive multiple vectors of explosive force, impacts, and just about all forms of weapons fire.
The top speed, maximum acceleration capabilities and the overall weight are all classified, but each is suggested to be an "impressive" number. The weight is rumored to be north of 10 tons, yet the acceleration has been witnessed to be quite rapid.
There are electronic countermeasures also employed and quite classified, but *and this is my own personal speculation* concern of an EMP is not really one of them as military hardware is capable of being shielded from this, so I am sure it is used in the limo.

There are several of these cars that are identical, because they are flown to wherever the POTUS will be going and are part of the advanced team. One is always around POTUS wherever he happens to be. The Air Force maintains the cargo planes used for the advance teams to pre-position the cars wherever POTUS may be going, and the car is one of the only things on that particular flight... Which also suggests how heavy it is.

As a general rule, military vehicles are fully exempt from emissions control rules - that the POTUS executive limo is operated by the Secret Service is likely only a formality, I would fully expect that while it is a very well-mannered and quiet vehicle when not "on alert"... It has little in the way of exhaust restrictions to prevent maximum power from being applied at a moment's notice.

Geordi said:

I know a fair bit about "The Beast" and there is a lot that none of us will ever know b/c it is quite classified by the Secret Service.

Public knowledge:
It is a diesel, currently based on a Kodiak truck chassis.
It might LOOK like a Cadillac limo, but that is where the similarity ends.
The tires are bulletproof runflat tires with special interior armor that prevents failure and allows continued operation without air.
There is a substantial amount of armor on it - how much and where is VERY classified, but it is expected to survive multiple vectors of explosive force, impacts, and just about all forms of weapons fire.
The top speed, maximum acceleration capabilities and the overall weight are all classified, but each is suggested to be an "impressive" number. The weight is rumored to be north of 10 tons, yet the acceleration has been witnessed to be quite rapid.
There are electronic countermeasures also employed and quite classified, but *and this is my own personal speculation* concern of an EMP is not really one of them as military hardware is capable of being shielded from this, so I am sure it is used in the limo.

There are several of these cars that are identical, because they are flown to wherever the POTUS will be going and are part of the advanced team. One is always around POTUS wherever he happens to be. The Air Force maintains the cargo planes used for the advance teams to pre-position the cars wherever POTUS may be going, and the car is one of the only things on that particular flight... Which also suggests how heavy it is.

As a general rule, military vehicles are fully exempt from emissions control rules - that the POTUS executive limo is operated by the Secret Service is likely only a formality, I would fully expect that while it is a very well-mannered and quiet vehicle when not "on alert"... It has little in the way of exhaust restrictions to prevent maximum power from being applied at a moment's notice.

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So it *could* just be a Duramax of some kind then, it sounds like.

Extra power from intercooling, direct injection, higher boost levels, better control over injection events thanks to commonrail etc. adding up to a lot more power than the poor old 6.5 could ever hope to muster.

I don't doubt the 10 ton number, and a old 6.5 would not move that quickly...

I doubt it's very quick at all. The '09-'18 version topped out at 60 mph according to Wikipedia. I'm guessing the quarter mile in 22 seconds or so.

AM General took over the rights to the 6.5L from GM, and since they knew the engine likely as good as or ever better than GM did, they immediately set to work and redesigned the engine and fixed all of its shortcomings. The new version is known as the 6500 Optimizer and it is actually a pretty tough engine, although not as powerful as some of the competitors' engines. But at least they no longer break.

Where is that engine used, Brian?

IndigoBlueWagon said:

Where is that engine used, Brian?

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AM General still builds the High Mobility Multipurpose Wheeled Vehicle (otherwise known as the "Humvee") for the military, both ours as well as our allies still use them.

Also, the Optimizer is available in the aftermarket. It is a popular upgrade for folks who love their older GM diesel C/K trucks as well as some P-vans (later known as Workhorse, until GM sold that division and was eventually taken over by Navistar).

Because most all the old 6.5L cores are no good for rebuilding, and the Optimizer is an easy drop in replacement for all of the older engines, and can be configured for both turbo and non-turbo arrangements. I have a customer with a '91 2500 Suburban that has one. It is not a 7.3L PS Excursion, but it gets the job done and has covered over 200k miles since install and the engine has needed nothing but oil and filter changes and a drive belt. That's it. They increased the oil capacity from 7 quarts to 10.5, it has a water pump that flows 50% more, and a much more robust block and cylinder head casting. He tows his race car and trailer all over the place with it. The 4L80E transmission has been rebuilt/replaced several times. The last time it got some fancy controller that is supposed to make it last longer, I think that has helped it a lot. There is a kit to convert these over to an Allison transmission but it involves a body lift for clearance on the GMT800 chassis.

Brian,
I am continually amazed at the wealth of information that we all get from you. For someone that is more of a turn the key and drive car person, it's great to get a glimpse into the minutia of the automotive workings.

I didn't mention it before b/c I wasn't certain of the information, but I have since found it on a couple different car enthusiast places (one linked above).

Yes, it IS a Duramax 6.6 liter, but not your garden variety version. The top speed is rumored to be 60mph b/c of the insane amount of armoring - 5-inch-thick glass isn't exactly lightweight either...

BUT the zero-to-60 time is 15 seconds. That's impressive enough, before you hear that it has turbocharging AND an Eaton Twin Vortices Series 1900 supercharger system. They can stuff a LOT of air into that sucker. It is also supposed to be B-20 compliant (although pretty much EVERY diesel engine can say that). With all the work it has to do however, it gets an eye-watering 8mpg. OOF.

There's really little reason for it to be fast. The entourage of secret service in escalades and suburbans, snipers along the route, and whatever other security measures can handle pretty much any issue that might pop up. In fact, speed might be a liability. Princess Dianna would probably still be alive if her limo had been limited to 60 mph.

Doubtful on that one - her limo hit a piling inside of a tunnel. Bashing into a reinforced concrete object while inside of a vehicle... Pretty much anything short of a TANK and you are going to have a bad day even at 30-40mph. She was also unrestrained.

I don't think it is so much the top speed as the acceleration, the capabilities of the limo are for the unexpected problems that the suburbans and etc can't directly deal with - OR the idea is to floor it and clear the area, and let the guns do the protecting while the National Command Authority is removed to a safe place as fast as possible.

Likely the engine wouldn't enjoy having eleventy-twelve pounds of boost stuffed into it, but if the engine only held together for 40 miles after an emergency-acceleration... That would probably be seen as acceptable if the POTUS is protected. That's all they care about, remember. Protect now, fix later. I'm kinda surprised they don't have a nitrous "panic button" system for even more emergency acceleration... But maybe it does and it's just classified.

Geordi said:

Likely the engine wouldn't enjoy having eleventy-twelve pounds of boost stuffed into it, but if the engine only held together for 40 miles after an emergency-acceleration... That would probably be seen as acceptable if the POTUS is protected. That's all they care about, remember. Protect now, fix later. I'm kinda surprised they don't have a nitrous "panic button" system for even more emergency acceleration... But maybe it does and it's just classified.

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A "scramble" button would make sense. It probably has one. Even better would be a small hybrid electric drivetrain that could add emergency power or take over altogether if the diesel quit.