Why no direct injection?

It is 51 HP in EV Mode.
2012 Toyota Prius Plug-in Hybrid Performance and Specs

The generation of Prius was introduced the Spring of 2009.

That means the next is expected just 2 years from now.

Toyota has already stated increasing engine efficiency is a big priority for it.

From the GS450H spec page, "

direct and port fuel injection" S

o, it might be like Subaru's newer FA boxer engines, found on the BRZ/FR-s. At certain RPMs is uses multiport fuel injection and at other RPMS it uses Direct Injection. At low RPMs and high RPMS it uses both injectors simulataneously, but at mid RPMS it just uses Direct Injection.

Who knows if the GS450H does it the same way. If it were pure DI I wonder if there would be more MPG. I'm thinking it will be a minor bump in MPG when Toyota renews the Prius with DI. HCCI engines will be what can bring it up significantly, IMO.

Yes the Subaru engine uses the lexus port plus DI system. There are a whole raft of changes including DI that toyota is using in the lab to raise efficiency of their normally asparated engines from 38% today to 42% in the future. The only reason a more efficient DI engine would not make the next prius is to keep cost down.

HCCI is one of those technology that just is not ready yet for production vehicles. It does not work well at high loads, and there are issues switching from HCCI to stoich combustion.

The issue toyota mentioned with atkinson and DI, is related to timing. With late intake valve closing the injector need to not put a cooling charge out until the valves are closed. This means they need to mix the fuel in a shorter period of time. Mazda seems to be able to handle this fine with their multi mode skyactiv engine with expansion of 14:1. I can't believe Toyota is having technical issues, but they may be having trouble getting around patents I would bet that any challenges will be gone before the next generation of prius comes out.

Maybe not the average Prius driver, but a lot of them do. Don't need 200 HP, 150 will help if they don't add weight.

I'd like to see a 300 hp 400 foot pounds of torque Prius model

I'd be first in line trading mine in for that baby

Mike

Skip hybrid, just get Model S P85.

I doubt you'll see turbo/super charging on a Prius anytime soon, but I think DI is a real possibility on the next gen. Make the ICE a little stronger, make the battery/motor more powerful, about 150-160 total hp would be sweet, and oh yeah 70 mpg!

Interesting to note the 2013 Accord 4 cylinder sedan and coupe engines are direct injected, but the 1.8L Civic gas is not, still multi-port. Honda does not list FI spec on site for the Plug-in Accord, but I'll bet it's DI.

What's the advantage of 3 cylinders over 4? Is the advantage from the displacement difference or is there something else that makes 3 cylinders more efficient than 4?

Less piston / bore friction from fewer cylinders, juan would think...

A 3 cylinder motor can still be built for Mad Powa. Need boost to get the torque or use lots of electric motor assist.

Mike

The higher the volume each cylinder has, the lower the losses (not only friction but heat also)...

Toyota's cheap...what else is new? have you actually looked around your car in and out?