The variable geometry turbo is very big news since its the first application in a gasoline engine. Previously VGT was only used diesel engines due to the higher exhaust temps found in gas engines. It took some very advanced metallurgy to bring this to market. The only other gas engine known to use this tech is the 911 turbo which is still a year away from production. Way to go honda. I would love to see this technology replace all of honda's V6 offerings or at least slot in between the 4 cyl and 6 cyl engines.

I read about the new 911 turbo w/VGT a couple months ago I think, some other intl auto show maybe? I wish more people would give turbos a chance, they can help improve both performance and economy.

Turbos also add complexity, increase underhood temperatures and crowd the engine compartment. They can make meeting emissions tests a challenge as well

The main thing is that you can get a four cylinder to produce V6 like horsepower and torque while keeping it's four cylinder fuel economy. Or the case of some of the SMART cars, a really really tiny (for a car) 3 cylinder turbo can have the horsepower and torque of a large four cylinder but with the fuel economy of a really really tiny 3 cylinder.

Yes a turbo adds more parts, a V6 has more parts than a I4 too. Turbos are not new technology, they've been well refined over the years and are vastly superior to the setups used in the 70s and 80s.

Audi's A4 with their new FSI turbo 2.0L I4 makes 200hp and over 200 ft-lbs of torque, in the FWD model with manual tranmission is still rated at 34mpg on the highway. That's better highway fuel economy than the 2.0L I4 Honda engines with 200hp by a couple mpg, not to mention the 50% more torque the VW/Audi engine has over those Honda/Acura engines.

Very interesting. I'll wait to see the fuel economy and emission specs before celebrating, though.

The current MDX is rated at 17/23 with it's 253hp 3.5L V6.

Supposedly Mazda is going to put their 2.3L turbo I4 with direct injection from the MazdaSpeed6 into other vehicles in the near future. I wonder if it will find its way into a compact or midsize SUV/crossover vehicle.

Eric, this already happend. Check out the Mazda CX-7

I don't know why this is such big news. Subaru has been selling 4wd turbo 4cyl crossovers for years. Looks like honda even copied the intercooler placement. The only real news here is the VGT.

Probably because the Subarus are more wagon than SUV, and Subaru's SUV the B9 Tribeca uses a non-turbo 6 cylinder.

Pardon me for being a couple weeks late on the CX-7's release. One article I read said the CX-7 is estimated to deliver over 23 mpg in combined driving. That would beat the current Acura MDX's fuel economy rating of 17 mpg city/23 mpg hwy and Subaru's B9 Tribeca's 18/23 rating (and any other AWD V6 SUV like thing I could find).

Wasn't a variable geometry turbo used on the old Shelby CSX (a performance version of the old Dodge Shadow)? That was a gas-burner.

Umm... Justin you are wrong about variable geometry turbos only being used on the porsche 911. In fact it's several decades old here in the US.

The Dodge 2.2L Turbo Mark IV series all had variable geo. turbos. (Dodge had Mark I thru Mark IV designations for different turbo setups.

It was an option in the charger, lazer, town and country wagon, and some pople even put them in the Omni.

If Acura brings this motor to production, I expect we'll see a lot of tuner fans adopting it, possibly along with it's AWD, into Civics and RSXs.

Though as far as Turbo L4s go, the 4G63 in the Mitsu Evolution still outshines this one.

It'd interesting to see a Honda line with a turbo; historically Honda has shyed away from turbos in favor of vtec and etc... to me this is a sign that Honda has reached a limit with how effective they can make thier vtec system.

I wouldn't want one in an SUV though :)
--Ash

Ash, variable nozzle is something completely different. Variable nozzle (VNT) worked on the compressor side and didn't have to deal with the high temps of exhaust gas. VGT works on exhaust side to elimate lag and is far more effective.

The I4 Turbos from Subaru have horrible turbo lag and are limp before 3500 RPM. I suspect Honda's VGT will be much better in this respect.

LochDhu, Subaru doen't build i4 engines. They make H4 and H6 boxer engines.

I haven't driven a turbo subaru before but I've driven several VW/Audi 1.8L turbos, I don't know if people say those have a lot of turbo lag or not but I never found it to be a problem. They felt like they had plenty of torque downlow as well, the specs say those engines reach their peak torque at just below 2,000 rpms. So I'm sure the lower rev range performance has A LOT to do with engine/turbo design & tuning.

The VW/Audi 1.8 turbo engine was reasponsible for changing a lot of people's minds about turbocharing back in the mid 90s. It pioneered the use of relatively small turbo to reduce turbo lag and increase low end torque at the expense of top end power. This made the engine feel like a much larger V6 while still retaining 4cyl fuel economy.

Put that baby into the TSX please, preferrably with sh-awd. Then we're talking about something exciting.

thats good my friend

Perhaps we can entertain the possibility of this engine in the 2007 s2000.