Featured New Corolla in 2026 with the revolutionary super-lean-burn engine, possibly 70+ mpg, PHEV version

I was under the impression that all of Toyota's non-performance cars would end up with hybrid drive trains. I guess for the USA that might be the case, who knows.

I'm glad it looks like they are figuring out lean-burn technology. I know lots of people ironically hate diesels then love lean burning gasoline engines, but in many ways these are the same type of technology with the same challenges and benefits. Lean burn (gasoline or diesel) burns more of the fuel in the combustion process instead of in the catalytic converter. If lean enough on a gasoline engine, it can virtually eliminate the need for a throttle, or at least keep the throttle plate nearly wide open even at low loads which therefore lowers pumping losses, much like a diesel engine. One of the main drawbacks is NOx formation and therefore mitigation. Diesels still have a theoretical higher efficiency due to not being knock limited with their compression ratio. However, the one benefit of lean-burn gasoline over diesel is it's easier to also lower particulate matter without the need for particulate filters and systems that inject extra fuel to burn out the particulates.

I do miss driving cheap econo cars with a stick shift. The GR Corolla is nice, but for me is too powerful and too pricey. But, in this time of age, a stick shift is not going to be the most efficient nor the most economical anyway, so oh well.

Still, if I ever buy a new car, the Toyota Corolla might just be that car.

 

Assuming this is the new engine family Toyota unveiled about a year ago, the rumor of an ICE option is wrong. Those engines were designed to work with some level of electrification.

The PHEV might use BYD's design.

Lean burn actually reduces NOx emissions from the engine. It also reduces the HC ones, which is where the issue arises when meeting regulations. Can't get the exhaust coming out of the engine clean enough, so emission treatments are needed. A three way catalytic converter needs the right mix of NOx, HC, and CO to convert them to CO2 and water. While NOx emissions are lower, that mix is thrown off by lean burning, and NOx emissions out the tail pipe are higher. The exhaust temps could also drop enough to impact the cat's operation too.

To handle NOx in a lean burning gas engine means adopting emission controls from diesels; either a trap, SCR with urea, or both. The OG Insight was lean burning and had a NOx trap. What this will need depends on the regulation limits.

Direct injection engines should be using exhaust filters. Some port injected ones might need them. Cars in Europe are already being equipped with them. I would guess lean burning means less particles being produced, has those are mostly from unburnt fuel.

 

Yeah, that's what I meant.

Basically if your catalytic converter doesn't work then your typical gasoline engine is going to put out way more NOx, HC and CO emissions than your typical diesel engine.

But, the dirtier engine is usually easier to clean up the exhaust. Or at least the one that has the "best" balance of oxygen and hydrocarbons in the mix.

 

I’d be interested in replacing the hycam with a Corolla cross phev, I’m just gun shy about their pursuit of higher efficiency engines being beta tested by their customers

 

Super lean burn should work great with Diesel Exhaust Fluid (DEF) which is available at any place that sells diesel fuel and parts.

Bob Wilson

 

I was looking at the article but could not find the parts about 50% engine efficiency and about the 70mpg. Can you point me to the source where you read that?

 

It's always best to wait for a couple years after a new generation comes out.

Who knows what they will decide to use.

One way of lowering NOx that hasn't hardly been tried is to cool the exhaust enough to harvest condensation, then take the condensation and inject it into the combustion chamber. The result would not only lower NOx but also effectively increase the octane allowing for higher compression ratios. The problem is you'd end up with water lines and the problems you get from freezing water. That and you'd need a lot of cooling to cool the exhaust.

 

i think so, and maybe the tundra? i'm no expert on what parts and/or engines are shared.

 

Upon further reflection, if the EPA is gutted, who will enforce clean air rules?

This would free all ICE makers to optimize efficiency at the cost of breathable air. Of course there might be markets that still value breathable air. But who needs to export to them?



Some of us remember Los Angeles, Denver, and Washington DC in the days before the EPA was formed.

Bob Wilson

 

+1!

 

Regardless who makes it...or what kind of car/light truck it is.

 

Isn’t that the point?

 

Perfect Massachusetts accent.

 

that should be; regahdless

 

I'll stick with burning electrons.

 

I don’t think you can do that.

 

Does anyone know what is the source of the info about the 50% engine efficiency and about the 70mpg?

The article link does not seem to support that.