Is Gen 5 Prius really better-looking than Gen 4 Prius Prime?

51 mpg city/53 mpg highway/52 mpg combined.

Gen 5 Prius XLE/Limited get 52/52/52 mpg. XLE/Limited AWD and Prime XSE/XSE Premium get less. Since most people like to drive their cars fast, the EPA highway rating will be weighted more in real-life driving for most, and Camry should beat the most common Prius trims in fuel economy, thanks to its more powerful engine.

 

It is easy to get a 38-mile BEV range in the city, which shows as about 6.3 mi/kWh on the display. I can get close to 35 miles on the highway (5.8 mi/kWh on the display) if I can keep my speed at 57 mph on the speedometer (55 mph actual).

My true (at-the-pump) lifetime average in mixed driving (mostly highway) without electricity use is about 67 mpg. Gen 4 Prius Prime naturally uses some battery SOC even in the HEV mode; so, that brings it up to over 70 mpg if you discount that. 75 mpg true mpg without electricity use is not that difficult to achieve. I achieved 120 mpg in long freeway stop-and-go drives. The mpg starts rapidly dropping at speeds over 62 mph on the speedometer (60 mph actual). So, Gen 4 Prius Prime shines at speeds below 60 mph.

 

Does it really help the Gen 5 Prius to have a hatch given that its trunk space is so tiny? You will get a much larger cargo volume with the new 2025 Camry.

The new 2025 Camry might perhaps even come with a spare tire.

 

Ah, OK, 51 mpg city/53 mpg highway/52 mpg combined are the EPA numbers for the previous-generation 2024 Camry HEV. Why do you think that the new-generation 2025 Camry HEV will get less?

 

Exactly—a can on wheels—and neither Gen 4 nor Gen 5 is high in the aesthetics department for average people. If I were primarily shopping for looks, there are much better-looking cars out there, but I got my Prius Prime for being a green car.

 

I think Toyota knew that going all-hybrid across all their vehicles was the end of the Prius, and that's why they came up with the radical new Gen 5 "non-Prius" design, which sacrificed a great deal of fuel economy, interior and cargo space, and convenience, with the hope that the Gen 5 non-Prius could be a sort of a boutique car that could still draw some buyers.

 

There was really no effort.

Camry HEV LE used a lithium-ion HEV battery vs. a NiMH HEV battery in the higher trims during the EPA tests, which is the main reason for the lower mpg numbers for the higher trims. It looks like at some point in the generation, more or less all trims switched to a lithium-ion HEV battery. That's also what happened with the Prius Eco vs. Prius EPA tests. Initially, only the Prius Eco had the lithium-ion HEV battery, which resulted in much higher mpg numbers for it in the EPA tests. Later, all trims except the AWD trims got the lithium-ion HEV battery, but Toyota never bothered to retest the higher trims with the lithium-ion HEV battery.

I am sure that all 2025 Camry trims will use a lithium-ion HEV battery.

The only other differences are the wheel size (16" on the LE vs. 18" or 19" on the higher trims) and 100 lb more weight on the higher trims.

Consumer Reports tested the HEV LE, and it is the top-rated vehicle among all vehicles. If I got one, I would get the HEV LE, as it is a lot cheaper than the higher trims.

This is what Consumer Reports said:

Best version to get

The LE hybrid is the best version with its 47 mpg, no compromise to acceleration or trunk space, and a quieter engine. Additional benefits include standard automatic climate control, heated seats and electronic parking brake, all for around $30,000. Note that the LE hybrid gets better fuel economy than the SE and XLE hybrid trims because it uses a lithium-ion battery.

Consumer Reports top-four vehicles among all new cars and SUVs—overall/road-test scores:

1. 2024 Toyota Camry HEV LE—93/94
2. 2024 BMW X5 XDrive40i—92/94
3. 2024 Honda Accord HEV Sport—89/96
4. 2024 BME X5 XDrive50e PHEV—88/98

These four vehicles are outliers in the ratings, well ahead of all the other vehicles.

 

No… You still don't get it.

It has nothing (or very little) to do with the wheels and weight.

Lithium-ion cells have a much higher Coulombic efficiency than NiMH cells—99.9% vs. 70%. This is the reason for the huge difference in fuel economy between the LE and higher trims.

BU-808c: Coulombic and energy efficiency with the battery—Battery University

Do you think that Gen 4 Prius Eco got 4-mpg-better fuel economy than Gen 4 Prius because it is 30 lb (1%) lighter? Of course not. The mass only contributes to the fuel economy in the EPA tests through Newton's second law (F = ma), and especially for hybrids, the effect will be much smaller, as you regain the energy spent during acceleration through regenerative braking during deceleration. So, 1% lighter could perhaps result in 0.1% better fuel economy for a hybrid.

2025 Camry will use a lithium-ion battery across all trims, and therefore, there will not be a loss in Coulombic efficiency in the higher trims due to a NiMH battery. There could be a small difference due to larger wheels, but that would be no more than about 2 mpg. There won't be anything radical like you see in Gen 5 Prius where they totally messed up the aerodynamics of the car by going berserk with 19" wheels on a tiny car.

 

It is the same wheels on the Eco and higher trims.

A small mass difference doesn't explain the huge mpg difference, especially for a hybrid with regenerative braking. If that were the case, you could easily get 80 mpg by weight-saving measures. Conversely, if you were carrying a passenger, your fuel economy would drop from 60 mpg to 30 mpg. The aerodynamic effect of the rear wiper is negligible as well.

The reason for the huge mpg difference is the difference in the Coulombic efficiency for lithium-ion (99.9%) and NiMH (70%).