Subaru Boxer Diesel Hitting the Streets

Cool. Add a turbo and bump up the power. Say hello to the 2010 WRX.

It is cool, but it's already got a turbo.

Very cool.

I was anti-diesel due to some bad experiences 20 years ago. That ended when I rented an Audi A3 2.0T in Italy in October. Fun car, plenty of power and great on fuel.

Jon

Yes. ADD a turbo and bump up the power. Is English your first language? :)

my is not so I do not get the joke :-(. The article says the engine is turbo diesel!

A.

Oh, ok, I thought you'd missed that. In fact I think you did, but are trying to snow us to reduce embarrassment :-).

It'd be hard to find room for ANOTHER turbo underneath though, without raising it to increase ground clearance! Even just a bigger one...

As I understand it, increasing the boost on a diesel doesn't require lowering the compression ratio, at least not in the way it's needed with petrol. So a bigger turbo would perhaps be an easier proposition with this engine.

The article reads like a press release. But I am sure this car will be reviewed in lots of magazines.

Oops, I just noticed that this is the Legacy, not the Impreza. Anyway, it sill is good news, since now Subaru will start selling some cars in markets like France, Portugal, etc. where gasoline engines are almost impossible to sell (for some models 90+% of the cars sold have a diesel engine).

Even in the UK, where the high price of diesel fuel means the maket is less "dieseled" than others:

"Indeed, the firm's UK operation reckons it could have sold another 4,000 cars last year with a diesel in the line up. And when full production comes on stream next year it expects 85% of Legacy sales to be oil burners."

Also, with the rules about average CO2 emissions (equivalent to fuel consumption) the number of diesel cars sold allows them to sell some more WRXs and STIs.

About the engine, the 150 HP are not particulary impressive. Yes, the VW TDI has only 140 HP, but:

- VW has a tradition of underevaluating the power, while Japanese brands are usually slightly optimistic;

- the 140 HP version is only the first power level. There is a 170 HP version and I think there was at some point a 200 HP announcement (did that engine ever appear ?)

- and BMW has a 204 HP engine.

- the Mitsubishi concept presented at Detroit had a 201 HP engine (2.2 diesel). I don't know if the production version of that engine will have the same power, although technically it should be possible.

So, I hope that Subaru will make an higher power version in the near future. But since they have an alloy block, they might not be able to compete with the TDI, etc.

[ I like alloy blocks (less weight, better cooling), but usually the maximum boost (and so the power) that they can endure is less than iron blocks. For instance the Mitsubishi engineers said about the new Evo X that the new engine (alloy block) could not be pushed above 360 HP. The Evo IX (iron block) had a 400 HP version (FQ-400, UK market). Also the new Nissan GT-R is supposed to be less tunable than the old skyline (iron block) which some tuners pushed to 700+ HP. ]

OTOH, the engine has 150 HP at only 3600 rpm. So, if instead of increasing the boost, Subaru increases the rpms to 4000-4200 it should be possible to get to 170-175 Hp without much trouble.

Just a few thoughts on this. Diesels typically generate much greater torque, but don't produce the rpm for big hp numbers. BMW's 3.0 diesel is rated at 265 hp, but with 425 lb/ft of torque. I don't know how or even if the equation differs for the relationship between the two in a compression ignition system vs gas/spark, but a diesel can be tuned for performance and the boxer design, with it's short crankshaft/camshafts and inherent balance, can somewhat offset the weight gain that usually comes with a diesel to accomodate the stresses of very high compression. The big issue is getting that torque on-line at very low rpm, and the lag that comes with a turbo compounds the problem. Now if you were to combine a turbo diesel, with its dual lag issues, with an electric motor that produces maximum torque from 0 rpm, you could have the best of both, or would it be all three worlds? So anybody up for a turbo-diesel hybrid boxer?

Just a few thoughts on this. Diesels typically generate much greater torque, but don't produce the rpm for big hp numbers. BMW's 3.0 diesel is rated at 265 hp, but with 425 lb/ft of torque. I don't know how or even if the equation differs for the relationship between the two in a compression ignition system vs gas/spark, but a diesel can be tuned for performance and the boxer design, with it's short crankshaft/camshafts and inherent balance, can somewhat offset the weight gain that usually comes with a diesel to accomodate the stresses of very high compression. The big issue is getting that torque on-line at very low rpm, and the lag that comes with a turbo compounds the problem. Now if you were to combine a turbo diesel, with its dual lag issues, with an electric motor that produces maximum torque from 0 rpm, you could have the best of both, or would it be all three worlds? So anybody up for a turbo-diesel hybrid boxer?

I'm holding out for a gas-turbine generator electric car.

Blair

I wouldn't hold my breath on that. Realistically, the diesel-electric hybrid is here. I work for a govt agency that's testing heavy commercial versions, using ultra low-sulfur fuel, right now and Peugot has a car ready to hit the European consumer market later this year. Could be the next step...