Featured Gen 6 Prius engine will be a “game changer,” achieve a 53% thermal efficiency

On their mystery number, I agree. However, their highway numbers are close enough. My previous Prius experience:

• First drive wait 1 minute - it typically takes 45-50 seconds for the catalytic converter to get hot enough for feedback, mixture control. If you have an OBD device, look for the catalytic converter temperature. Just wait at idle until it leans out.
• 63 mph - matches the highway numbers. Faster is less, slower is more.
• 22 mph +/- 3 mph - peak efficiency. The slowest cruise control setting, 26-27 mph. Find your minimum and add 2 mph for longest, most efficient speed.
• one hour minimum - this is long enough to reduce the startup and initial inertial load to less than 10% of the trip

These simple rules are how I got my 1,000 mi tank. Don't fiddle with 'feathering' or 'engine off' nonsense but rolling in "N" works on very long, shallow, downgrades.

Bob Wilson

 

I find them to be sand-bagged. Pessimistic. De-rated to lower than actual, outside of foul weather.

Maybe I don't speed fast enough?

Agreed there.

 

Ran into the same. I recalled the adjustment might have started a year or so after the start of the requirement, but left it off the post for brevity,.

These energy efficiency numbers are for their thermal efficiency. It is the amount of the fuel's thermal energy gets turned into work. The lower the percent, the less fuel the engine uses to turn the crankshaft. The rest is wasted in terms of the engine doing useful work.

You are moving beyond engine efficiency into vehicle efficiency. These are two different, but related, things. An engine can go into numerous different vehicles. All with different shapes, weight, equipment, and features. Put a car together wrong, and even the world's most efficient engine will return crap fuel economy.

Without knowing the specific car, talking vehicle efficiency of an engine is pointless. Knowing an engine's thermal efficiency is important because it sets the bar for a car's potential efficiency. The air drag, rolling resistance, drive train efficiency, etc. all subtract from it to get to the vehicle efficiency. All else being the same, putting a more efficient engine into a car will yield better fuel economy. It's how the OP of this thread estimated 75mpg for a Prius using Toyota's new engine, which is going into the new Corolla.

 

absolutely agree. I am sure they are getting these figures in the the lab, but when it goes into a real car cost, pollution controls, and reliability usually drop this figure except in rare examples like the vw XL1 which never got an epa rating because all 250 were presold outside the US.

 

Well fine, just be logical. And keep it up!

I hope that 75mpg does become a reality soon. That would be awesome. I've been driving around a vehicle these past few days that is averaging 13.8 mpg.

 

It sounds like the next Corolla will be the first model to use these new engines. We'll see how much of an improvement then.

The US will likely have to wait until after Japan and Europe gets it though.

 

Thats gotta hurt, especially if you've got a 20 gal tank or larger. Not fer nothing, but - is the early 80's I was hurtin pretty bad in the wallet and my '72 gold / white vinyl top Charger / 318 was gettin 10. $3 at the pump would get me 25 miles.

 

Got me thinking about firsts we don't see in this country. I posted about the new tech in the 21 Aqua here a couple years ago. Since then there's been an update to the Toyota Worldwide site on the model and I also found a half hour youtube about the 2017 Aqua upgrades. Links respectively below.

Toyota to Launch All-New Aqua | Toyota | Global Newsroom | Toyota Motor Corporation Official Global Website

ps: don't forget to do the conversion of km/L to mpg
from the article Aqua is rated at 35.8 km/L ( obviously that's not an EPA rating ) still ! ! ! ! ! ! !

once the drive by wire programming features are more fully / better understood, so is the B mode braking by wire..