2012 Jetta Hybrid?

Does anyone know more about this car? I'm trying to used the search function but my phone is not cooperating.

http://www.torquenews.com/106/volkswagen-jetta-hybrid-coming-2012-detroit-auto-show

VW has had prototype hybrid powertrains running around for years. The following is only conjecture at this point, but based on what we've been seeing from VW in the recent past, the powertrain is likely going to be as follows.

The engine is the 1.4 TSI turbo 4-cyl gasoline engine with direct-injection. The latest version of that engine has a system to shut down two cylinders when the engine is running at part load (sorta like GM's displacement-on-demand V8 but this one is on a DOHC 4-cyl engine). Apparently the 1.4 TSI with cylinder shutdown is able to do 70% of the European city test cycle on two cylinders, and the fuel savings are substantial in city driving (it runs mostly in 4-cylinder mode on the highway, so there's not so much benefit there). It's an interesting engine on its own.

The transmission is almost certain to be a DSG. It isn't known whether it will be the 6-speed wet-clutch DSG that we've known up to this point in North America, or the 7-speed dry-clutch DSG that is already in production in Europe.

Previous VW hybrid powertrains (all prototype only) have had the electric motor sandwiched between the engine and the transmission input shaft, with a clutch between the electric motor and the gasoline engine so that it could operate in all-electric mode. I don't know how that works with DSG which inherently has two clutches on the transmission input shaft. Three clutches and a motor are a lot of stuff to jam into that very small space.

Thanks for the information, GoFaster.

It appears to be a promising alternative for those who love VW but need better city mileage while still getting the superb highway mpg of the TDi. It will likely do worse in the winter than the TDis. Hybrids are known for a drop in cold weather MPG.

I doubt if it will match TDI for straight motorway driving. Hybridizing doesn't contribute anything whatsoever in those conditions. If they're using the 1.4 TSI with cylinder shutdown, it will be operating in 4-cylinder mode under motorway conditions anyway, so the cylinder shutdown system won't help. At that point it's just a regular gasoline engine (albeit a small-displacement one with direct-injection) carting around a bunch of extra weight because of the hybrid system.

TDI will remain the drivetrain of choice for long-trip drivers. The hybrid system will be good for those who have a lot of stop and go city conditions. More choice is good.

GoFaster, that is actually inaccurate. The hybrid system does contribute to highway efficiency by supplementing the weak gas engine. There is not other vehicle that is the size and weight of say the Prius that can match it on the freeway except a turbo diesel and even that simply matches it. Sure hypermiling any car can produced extraordinary results but a highway driven Prius will throw down 55mpg to 60mpg at 60mph to 70mph. I admit that the TDi doesn't lose as much mpg as the Prius does when driven at 80mph or more. The TDI torque is pretty sweet.

I'm posting a few pictures to help illustrate my point about how the hybrid system functions on the freeway. I do not know how the Jetta hybrid will compare on the freeway vs. the TDi model but if the EPA rating is higher or similar for the hybrid version then I do not think the TDi is going to surpass it by much if at all on the highway. I think it will be great to have the choice of 3 different systems though, especially for those who want to run biodiesel!

2010 Prius MPG vs. MPH testing (courtesy of Bob Wilson)


My morning commute of 46miles of 98% highway. This pic shows my current tank which is comprised of 95% highway driving at 60-65mph. Below this is an elevation map which shows why I'm not getting 60mpg despite my low speed.


This is what a flat freeway at 60mph looks like for a full tank.


Commute elevation map. The y axis is x10 so 1200ft. max. Big hills kill MPG.


Picture of my scan gauge while cruising at a steady 63mph. You can see by the 16.5HP status that I am not cruising downhill or lifting off the throttle. The average HP required to run at that speed is between 12.5 and 17HP.

Prius will do no better in straight constant-speed driving than the same vehicle (same aerodynamics) with the same engine and the same gearing but without the hybrid system - that's what I mean. Yes, the hybrid system helps driveability somewhat (only a little) with acceleration and makes the car feel less underpowered than it otherwise would be. Keep in mind that the Prius has a gasoline engine that has some unusual tuning for efficiency. The Prius comparison is difficult because there isn't another vehicle in Toyota's lineup that is a direct equivalent but without the hybrid system. The aerodynamics are part of the package ... but if you did that to a non-hybrid, it would benefit, also.

The other hybrid vehicles that have straight-gasoline direct equivalents are a better comparison for what the hybrid system contributes, and it tends to be a big difference in city driving, not so much in highway. Remember that the highway test cycle still includes some speeding up and slowing down.

example
2011 Hyundai Sonata hybrid EPA 35/40
2011 Hyundai Sonata 6AT EPA 22/35 (much bigger difference city than highway)

Some of that comes from the hybrid system eliminating the torque converter.

I still disagree. The Prius HSD is completely different thank any other hybrid system and thus works differently. The only thing it shares with other hybrids is the use of an Atkinson cycle engine instead of the typical Otto cycle engine which has more power but is less efficient thank the Atkinson cycle.

The closest thing to a Prius is the Toyota Matrix which has slightly less HP and is lighter. It only puts down 32mpg highway.

I respect your opinion and am not trying to champion hybrids over conventional cars but because I drive one and spends hours a day reading about them and even do a podcast on advanced technology vehicles i'm fairly well versed in the way they work. I constantly watch the HSD system assist the engine while driving at freeway speeds. Without it there is not way a 3000-3100lb car would be able to get 50mpg EPA highway or 60+ mpg with a little effort. Even the compact car segment cannot touch the Prius numbers and they are much smaller and lighter cars. The Prius just classifies as a mid size vehicle.

I do agree with you that the amazing numbers are city mpg figures but a lot of people then assume for some odd reason that the Prius and other hybrids must then suck at highway mpg but the truth is they don't. Hybrids simply have city mpg that nearly matches or exceeds highway mpg (low variation) whereas conventional vehicles suck with regards to city mpg and have better highway (large variation) or in the case of the TDi they have amazing highway mpg compared to city mpg.

The other cars you listed were not designed as dedicated hybrids which is why the hybrid efficiency is slightly better than the gas only option. They are getting better though. The 2012 Camry hybrid now has 200hp and gets 43mpg city/39mpg highway and starts at $25,900.

,A gainplease don't take this as a put down to TDi technology. I have great respect for those cars. I just disagree with your idea of how hybrids or at least the Prius family of cars work. Toyota flew a bunch of us to Detroit for the unveiling of the 2010 Prius and held a private event where we could see the new cars and badger the chief engineer with thousands of questions. lol

Question to be seen: Will the Jetta hybrid accept regular gasoline (premium recommended) or will it be strictly premium gasoline only?

Max Period said:

Question to be seen: Will the Jetta hybrid accept regular gasoline (premium recommended) or will it be strictly premium gasoline only?

Click to expand...

I hope it will run on regular. The volt has received bad press due to it's premium requirement. Hopefully the Jetta will learn from that mistake. I may provide tuners with an extra bit of cushion if drivers have the ability to upgrade to premium instead of having performance already maxed out.

Okay, Ford's planetary - powersplit system is essentially the same as Toyota's.

Ford Fusion hybrid 41 city 36 highway (uses an Atkinson-cycle version of the same engine as ...)
Ford Fusion 6AT 23 city 33 highway

Toyota Camry hybrid 31 city 35 highway (uses an Atkinson-cycle version of the same engine as ...)
Toyota Camry 6AT 22 city 32 highway

Bigger difference city than highway every time ...

Max Period said:

Question to be seen: Will the Jetta hybrid accept regular gasoline (premium recommended) or will it be strictly premium gasoline only?

Click to expand...

There's no way to know this for sure, but every VW TSI engine thus far has "recommended" the use of premium fuel. They'll run on regular, the engine has knock sensors to protect itself, but performance and fuel consumption are best when premium is used.

GoFaster said:

Okay, Ford's planetary - powersplit system is essentially the same as Toyota's.

Ford Fusion hybrid 41 city 36 highway (uses an Atkinson-cycle version of the same engine as ...)
Ford Fusion 6AT 23 city 33 highway

Toyota Camry hybrid 31 city 35 highway (uses an Atkinson-cycle version of the same engine as ...)
Toyota Camry 6AT 22 city 32 highway

Bigger difference city than highway every time ...

Click to expand...

S, urethe city mpg is where the largest gains are to be found with hybrids but the highway mpg also improves by a decent amount. Consider the 2012 Camry at 200hp and 43/41/39 (city, combined, Hwy) vs. the non- hybrid at 25/28/35 ( city/combined/hwy ). The hybrid sports more HP and TQ and still gets better mpg. I agree the hwy mpg is not a huge gain but show me a similar class car that gets 39mpg on the hwy that isn't a hybrid or that can pull off a 41 mpg average.

The point is that hybrid technology benefits hwy driving even if it's not as dramatic as the city benefits. This doesn't even go into further benefits when using hypermiling techniques unique to hybrids when on the hwy.

It will be interesting to see how VW pulls off the hybrid stuff. I hope they do an excellent job unlike some of the other manufactures.

F8L said:

It will be interesting to see how VW pulls off the hybrid stuff. I hope they do an excellent job unlike some of the other manufactures.

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And on THAT, we are on the same page.

In fact, if VW doesn't prove to me that they fix the HPFP issue on the common-rail engines AND if they put the hybrid powertrain in the next VW Golf (I don't like the current Jetta) and this engine has the two-cylinder shutdown system ... it could very well be my next car. If not, Ford Focus here we come.

One thing to note is that hybrids have the potential to seamlessly do one hypermiling trick, at the cost of abusing the batteries badly.

One popular trick for hypermiling, especially on gasoline engines, is "pulse and glide" - get the throttle open pretty wide, reducing pumping losses, accelerate, then shut down the engine and coast. Repeat indefinitely.

A hybrid can actually do this without changing vehicle speed - shut down the engine and run electric only, then once the battery is depleted, restart the engine, and switch to regenerating from the electric motor(s) while the gasoline motor is propelling the car.

Works better on a flywheel or hydraulic hybrid, though, rather than a battery hybrid.

GoFaster said:

The engine is the 1.4 TSI turbo 4-cyl gasoline engine with direct-injection. The latest version of that engine has a system to shut down two cylinders when the engine is running at part load (sorta like GM's displacement-on-demand V8 but this one is on a DOHC 4-cyl engine).

Click to expand...

Can we stop right here, let it do dual-fuel premium/E85, and shove it in the smallest chassis they can federalize?

E85 + Boost + Compression = FUN!