New Lexus RC F expected to feature Atkinson mode!...

Sounds cool! Not a fan of turbo's (partly due to my Volvo probably suffering from a malfunctioning turbo ever since I got it...), so if similar numbers can be achieved NA style, I'm interested...

What's electric phasing? Not full electronic control of the valves I assume? (Few years back that was considered not viable for decades to come).

 

Honda's new Accord hybrid does the same thing (switches between Otto mode and Atkinson mode). The Otto mode activates above 3000 rpm when the VTEC kicks in.

 

Isn't it what mazda does in skyactive (minus the electric phasing)?

 

Sounds like the 6.0 engine used in the GM hybrid trucks.

 

skyactiv include electronically controlled lift to provide a number of modes including one that is like atkinson, and one that is like otto. It also has differently shaped combuston chamber and a specially designed exhaust manifold to allow for higher compression (13:1 with regular, 14:1 premium) verus 12.3:1 on the Lexus.

I'm sure the lexus has cylinder idle technology as its a 8 cyclinder. It also has port injection to go along with the direct injection. That may have some advatage but I am not sure what it is.

 

It is also direct inject, which allows the higher compression with lower fuel octanes.

 

I read the article and it confirmed "Motor Trend" is a bit lightweight when describing engine technology. Claiming the engine rpm increased because of engine friction reduction is so wrong. Add to that the description that the exhaust gas pressure will be atmospheric . . . Still, it will be worth while to get the SAE paper in April and read about the engine. As for the rest of the car, it is aimed at a different buyer.

Now if they can put the engine in their pickup truck . . . that would be impressive. It would pretty well put the diesel pickups to shame with better emissions.

Bob Wilson

 

Except for particulates.

 

Of course they could put it in a pickup truck, but why would that be impressive. A sports sedan ice is tuned quite differently than a truck. Let's wait for the epa numbers to come out, but I would bet they will be better than the IS F, but worse than the M3. Its not going to be in 328d territory.

 

Noooo.... DI gasoline engines have measured 10 times more soot than a modern filtered Diesel engine. DI lean burn also puts-out more NOx than a standard gasoline engine.

 

This is the news article about it, TUV Nord Testing Firm: Direct Injected Gasoline Engines Emit More Particulates Than Diesels | The Truth About Cars
Ten times more than diesel is likely the worst case.

These two mention that it will tough for GDI to meet upcoming emission regulations without a particulate filter.
http://www.swri.org/3pubs/ttoday/Summer11/PDFs/ParticleEmissions.pdf
Particle emissions from petrol cars | Transport & Environment

The abstract of this paper mentions previous research showing GDI produce one magnitude more particulates than a port fuel injected engine.
ORA Thesis: "Measurement of particulate emissions from gasoline direct injection engines" - uuid:19e8dc75-9873-4b76-831d-3878fd048169
A paper of previous research.
Particulate Emissions for LEV II Light-Duty Gasoline Direct Injection Vehicles

This presentation had a nice graph(p. 3) showing GDI particle emissions range between PFI/filtered diesel and unfiltered diesel. I'm too lazy to pull it out and post directly.
http://www.aqmd.gov/tao/ultrafine_presentations/session6_5_mattimaricq.pdf

 

The SAE paper abstract stated a 14 mg/mi average on cold start by the federal test procedure(FTP). The average of the FTP results was ten times LEV II PFI vehicles that were tested in the past. They would appear to exceed the PM requirements applied to diesels in the US. Need to buy the paper to get the details.

The ORA thesis has a downloadable Word document. It would appear the latest generation of GDI do better in regards to particulates, but still worse than PFI, and thus filtered diesel.

 

Yes I expect going from a 4L 8 to a 3L turbo 6 should drop fuel consumption on the epa tests to around 20 mpg, from 16 combined. That would be in line with the 335i, with a little reduction for stickier tires and more boost. Drivers should not hit the inefficient range of the ice unless they push it, and you don't push it on cruze control or on the tests.

I don't know how drivers will do on your Spritmonitor site though, they may be pushing, but they did get around EPA numbers on the M3 and IS-F. I think Lexus is smart to be using their excellent v8, and making it even better for this car. Many people do like the sound and feel of a v8 in this segment, which is why bmw introduced one. Lexus seems to be able to make a better normally aspirated V8, bmw a turbo inline 6, these are the best engine both companies have. Lexus seems to have more expirence with electronic power steering, but bmw may catch up a little in the next m2/m4. BMW has more pressure on their corporate co2 in europe and cafe in the US than Lexus.

Detroit Auto Show: Lexus unleashes high-performance RC F Coupe - latimes.com

It sounds like lexus has targeted the upcoming bmw M4 and audi S5 well. There is also an RC hybrid that europe will get but probably not north america, for those want the luxury and handling, but choose efficiency over acceleration.

 

In 2016 EU regs will require Gasoline DI engines to include the same particle filters on DDI engines. So it's a real issue that governments are concerned about
.