CNet review: Jetta Hybrid beats even diesel fuel economy

I believe you are thinking of a NOx trap system. These catch the NOx in a zeolite, which is periodically recharged by adding diesel to the system. The Jetta uses such a system. The Passat uses SCR, and gets around the fuel economy as the smaller Jetta.

NOx adsorber - Wikipedia, the free encyclopedia

 

I was thinking of future systems. I thought the traps were not nearly as effective, and reduced fuel economy as they need fuel to clean the trap and it adds more of a load for the engine to push out the exhaust.

 

Think I've heard of such systems. The one I came across has another catalyst that produces the urea or ammonia. The in product was diesel, so the drop in fuel economy wasn't offsetting the drawbacks of the urea tank. Seems a ways down the road.

 

bottom line - if you want to meet US emissions and not have a urea tank a diesel hybrid is not going to outperform a gasoline hybrid by very much. I think the vw diesel gets a peak efficiency of 42%, toyota is claiming 38.5% on its di 2.5L engine soon to be introduced. That is only 3.5% boost in efficiency theoretical - but add the load of a NOx system and the extra weight, its maybe 2%. 40.5/38.5 = 5.2% add in the 10% more power in a diesel and we get 15.7% more efficient. Say you get 45 mpg, now its 52, but you are charging 2K more and the fuel costs more in the US. Driving 15K miles per year comes out to 333 gas, 288 diesel or a difference of 45 gallons a year. It will take over 10 years to pay for that diesel and its likely to have more unhealthy tail pipe emissions than an atkiinson or turbo mainly running miller cycle. That initial hybrid up charge - about $4K in the camry and fusion comes with more power and a much bigger gain in efficiency. Make it a 6K upcharge and drop the power, and you are going to sell less.

I would bet if there is a hybrid diesel sold in the us it uses a separate catalyst tank.

 

2013 Volkswagen Jetta Hybrid Review and Road Test - TTAC's Alex L. Dykes Published on Jan 17, 2013

 

If the higher price of diesel in the US continues, a hybrid diesel would never cost less than a petrol hybrid over time.

I came up with a slightly better performance boost from the hybrid addition to diesel than AG came up with, but we both agree that it is pretty darn puny. Seems silly to build that car at all.

 

Personally, I'm waiting for the Stirling-hybrid.

Bob Wilson

 

Stirling on what fuel? Wood chips?

I would like to see Stirling on exhaust gases from a normal Prius engine, only 10% efficiency for converting hot exhaust to energy would gain 5 % in total Prius engine efficiency. The problem would be the size of Stirling engine added to the car. Maybe 10% efficiency can be achieved with simple Thermoelectric generator.

 

Treated, coal dust, with a water spray. Treated to remove as much of the mercury or other pollutants as possible. Heck, I have no problem with it being coke if it burns cleaner.

I would use a compact, air-preheating, sulfur reduction, fluidized bed with water injection to reduce NO{x} with post processing to harvest any methane (aka., this is the receipt for manufacture gas.) I would expect it to take about 5-10 minutes to reach operating temperature but meanwhile the car runs in EV mode.

Once running, sustain constant speeds and use excess power to recharge the batteries. When parked, combustion is turned off and the latent heat runs the Stirling to complete the traction battery charge.

If the traction battery SOC gets too high, turn off combustion until the traction battery reaches a low enough SOC. There are some tricky control laws in here but nothing that microprocessors with sensors and sensible, field upgradable, software couldn't handle.

For the exhaust of the current engine Prius, I'm more a fan of Rankine cycle since the temperatures are ideal for a steam generator powering a turbo-alternator. Then dump whatever power is generated back into the hybrid drive.

A 100% recovery condenser is not needed as it can also capture exhaust H{2}O. So I would dump the exhausted steam into the tail pipe headed to the open-ended, condenser.

My thinking is all exhaust passes through a labyrith, aluminum 'can' thickness, condenser built into the current bumper cover and replacing the current existing foam block. On crushing, the aluminum pipes are formed into a collection of 'bellows' that compress and deform to abosorb the impact impulse. Thus the larger 'air trap' volumes would further mitigate impact impulse and mass produced, the material costs would be trivial and easily recycled.

FYI, this also replaces the muffler.

Bob Wilson

 

I had a sit in this one at the car show. Like most VWs, the driver's seating is ace. I wish Toyota would take some clues from VW and Honda's excellence in seating and steering wheel placement for the next gen liftback Prius.

You lose some trunk space with Jetta hybrid. But gain quite a bit of power and torque. Some people will not buy the Prius shape no matter what, so this is another good alternative for those who can gamble on VW 'reliability'.

 

That guy from from TTAC, Dykes, gives very good reviews IMO, but have to disagree that Fusion hybrid is 'less' than this Jetta. Fusion hybrid starts at $27.2k and video listed jetta hyb starting in $25k range. ...

Also, it's getting annoying to see the '47 MPG' Fusion and C-Max EPA rating. Saw commercial last night bragging about more power in C-Max than Pri v and better FE at 47 ..... BS.

As for Jetta, I say a welcome addition to the hybrid space. Some people will like the conventional transmission of Jetta hybrid over HSD. Sounds like VW needs to smooth out all the braking though.

Catch that about the Jetta hyb power seat? Only the back of seat bottom adjusts up/down? ewww.