How can they improve the fuel economy of the next generation Pruis?

Yes, they could probably cut weight in the frame and make it more aerodynamic with one wheel in the back with a hub motor. That would make it street legal in the us.

Aptera is the closest to having a street legal 3 wheeled highly efficient electric motorcycle. I think nissan/renault could be successful building some in america.

 

But are three wheels less safe than four? The Twizy is classed as a four wheel motorcycle (only the French could come up with that!), and it is much less safe than a car BUT it was suggested instead of an electric scooter, so would be much safer than that.

The Twizy is proving a surprising hit here, mainly with guest houses in national parks; they're ideal for driving down the narrow, winding roads designed for pack horses 400 years ago. Great to explore the countryside as they're so quiet.

Renault Twizy hire and B&B in the Brecon Beacons, Wales
Electric Car Hire in The Lake District

So who will be first to get one in the US then? (even if you don't ever take it on the roads)

 

Indeed you are, but the Twizy was a suggestion to riding a scooter. Get hit on a scooter and you're history, or a motorcycle or a pedal cycle or even as a pedestrian. You'd be mad to take a Twizy on a freeway but for quiet roads it is an alternative to a scooter.

 

I have to go visit my cycling buddy in the hospital this morning. He ruptured his spleen on our trail ride Thursday, falling off a curb watching for a gap in traffic. He's a devote athiest so his guardian angel was probably at the pub already.

 

Most of which is due to the higher energy content of the fuel. This higher energy content is the carbon so CO2 emissions are higher per mile in a diesel than in a gasoline engine.

Our Prii use an Atkinson cycle engine which is kept in an optimal operating range by the HSD system. In that operation, it is also more efficient than a standard gasoline engine but not quite as efficient as a diesel (efficiency is enhanced by the higher compression ratio).

You will NEVER see hydrogen fueled vehicles in mass production as they are not now, nor will ever be cost effective. You should not believe everything that you read. The research into hydrogen vehicles is part PR and part foolishness in our government bureaucracy.

JeffD

 

"The NREL PEC system produces hydrogen from sunlight without the expense and complication of electrolyzers, at a solar-to-hydrogen conversion efficiency of 12.4% lower heating value using captured light."

 

For my situation, a block heater was an energy loser, once I include the electricity needed to keep a large block of metal, outside, warm. It looks better on my MPG meter, but not to my wallet or my planet. YMMV, but do the math first.

 

It's also lower efficiency than a good photovoltaic (AKA solar cell) creates electricity from sunlight and this electricity can power a car more efficiently (about 50% given battery losses) than hydrogen.

JeffD

 

I once did the rough math. The block heater draws 400 watts, and with our rates it worked out to between 6 and 10 cents per hour. A couple of hours (one in a pinch) is effective, pretty much year 'round, with our temperate climate. A lot of times it ends up running a lot longer than that though, it can be difficult to nail departure time, and I'll err on the side of excess.

I'd be satisfied to almost break even, since it's a fairly trivial cost (apart from the post-delivery installed cost!), is (I think) beneficial to the engine, and get's the interior comfortable quicker in winter.

 

Electric generating shocks and struts.
Electric generating seats that can slide side to side (maybe not the driver!)

 

seems like a plug would help with a block heater, cabin pre-conditioning, battery thermals, the occasional battery conditioning, and topping off the existing HV battery. restricting the plug to off-peak consumption and minimal amperage should be cost effective. the burst amperage for the block heater could be drawn off the HV battery or better yet off of the hot side of a heat pump cooling the cabin and battery. If the cabin doesn't need cooling, maybe cooling the intake air is worthwhile.

 

The future is already here, for my usage the PIP gets me more than 2X gas mileage compared to my 05. Perhaps further refining the PIP is the answer.

 

One more item from the SciAm article that no one else seems to notice: electric valves, abolishing the camshaft.

With this, software allows just about any gasoline engine to switch between Otto cycle and Atkinson cycle on the fly, with a wider Atkinson cycle adjustment range than Toyota's mechanical valve adjustment system currently allows.

 

As long as there is not a clearance issue in case of an actuator failure

Mike

 

IIRC they are limited to 25 mph to be street legal. That caps a lot of demand. Yes they don't have safety devices mandated in a car, but neither do motorycles and bicycles. England and Germany with lower fatalitiy rates allow these things. As long as the buyer takes the risk, I don't see why we can't have these toys. It is quite different from the prius that is a very efficient very safe vehicle.

 

You recall correctly, they are legally limited to 25mph, although many have been tweaked to give more speed. They also can only legally be used on roads with speed limits of 35mph or under. I live in a very NEV friendly small city. You can reach most of the town in an NEV, they have added a few NEV lanes on sections of 45 mph roads so you can get to more parts of the town.

 

About 50% of the 25% and the other 50% of the 25% greater efficiency of a Diesel is due to much higher compression ratios and turbo charging.

Diesel would currently be the only way for 2015 Prius to be a 60 mpg car. The only other possible way with current technology (which is pretty much the determinant for 2015 production which is being planned now) would be to go to the Lithium ion batteries and store more captured energy.

 

I'll take two.

 

Toyota has variable valve lift technology called valvematic which allows it to do the same tricks as electronic valves, but requires a camshaft and its friction, . The problem with both systems is they are currently expensive. fiat with multi-air and mazda as part of skyactiv have brought out less expensive systems to do this. I would expect that by the time the next prius is out, toyota might have brought costs down to add variable valve lift on the intake valves. There are no technical hurdles, its just about costs.

I would think they would build the valves to fail closed instead of open, like the current valve designs. If you have 2 intake valves per cylinder and one sticks closed, its likely you don't get full amounts of air, and end up burning rich on that cylinder. Its time to get the valve fixed quickly with more than one failure.