Featured Toyota And The Rotary Engine

It looks like @bwilson4web may have competition for his i3 REx.
Are they trying to compete with the Volt by pairing an EV with an inefficient ICE?

 

That is a 2014 BMW i3-REx. But I can appreciate the importance of highway efficiency which depends on:

• low aerodynamic drag - cooling engine drag is a function of engine efficiency
• low rolling drag - lighter weight is goodness
• high engine efficiency - Wankel expansion ratio is a challenge and seal leakage but there has been significant progress

I welcome the improved Wankel technology and hope it shows up when I need to replace our plug-in hybrids in 10-15 years.

Bob Wilson

 

Why the emphasis on the year? It is less than 4 years old and according to an FHOP thread here the average age of a car on the road is 12 years old. Your SUV is a youngster.

 

". . . when I need to replace our plug-in hybrids in 10-15 years."

I especially look forward to BEV bigots in 10-15 years having a conniption fit when I buy another plug-in hybrid. <grins>

Bob Wilson

 

pie in the sky, i guess someone has to think about future possibilities, but toyota is dead wrong, it's going to be all ev.

 

amazon will blow toyota away with the e palette stuff.

 

looks like a press release without a product. Its just trying to get pr for toyota phev.

Well sure, but mazda has gotten consumption pretty low, the real problem is efficiency. They can counter act this by restricting rpms, but it won't be nearly as efficient as a atkinson or miller cycle standard ice. You can increase efficiency by adding di or port + direct injection and turbo charging, but these add to cost, reducing the cost advantage of the rotary.

When you add an ice, even a rotary, you need to add a radiator, egr, and a catalytic converter. The rotary engine may be smaller, lighter, and less expensive than a similar powered ice, but when you add these things the savings are not that great.

For cars like this I doubt you can do much better than atkinson as long as cost/efficiency/size trade off permits it. The 2.5L 176 hp engine in the 2018 camry hybrid is pretty much state of the art except for adding electronic variable lift on the valves. Size it down to 1.5L and you still get 105 hp, which seems better suited to run efficiently on the highway compared to a rotary, and even has enough torque to drive the wheels instead of just a generator.

Want more efficient and smaller, the miller cycle not rotary is the answer. A 1L-1.2L 3 cyclinder blown engine would be smaller but more expensive. Probably the most expensive but most efficient would be a 120 hp 1.2L skyactiv-x varient with electronic lift on exhaust and intake valves, di+pi, turbo + electronic supercharging. Do a iron block/aluminum head for small size, quick warm up, and its a truly small efficient engine.

 

Full disclosure, I'm not interested, yet, in making a high efficiency, Wankel engine. In theory,

• delayed intake port closure is possible - even variable to replace the throttle body butterfly valve. A single rotor works but three would be perfect so the exported intake charge feeds the next rotor.
• oil pressure fed seals - so lubricating oil only feeds the seals. This eliminates the fuel-air mix.
• Wankel specific spark plug - arcs to rotor electrode or seal.

Bob Wilson