3 ms·

I'm a bit confused by your numbers, and I suspect we may be mixing multiple units of measure (maybe due to different definitions of gallon?). The 2021 Prius Pr

I'm a bit confused by your numbers, and I suspect we may be mixing multiple units of measure (maybe due to different definitions of gallon?). The 2021 Prius Prime is rated at 53mpg highway. Let's assume that is optimistic and it gets 50mpg. Its fuel tank holds 11.4 gallons, but you don't want to run it dry - let's say 10 gallons are usable. That is a 500-mile (~800km) range after the battery is dead. At 75mph, that requires stopping to refill the gas tank every 6 hours and 40 minutes. The most efficient 2012 Honda Civic is the hybrid, which is EPA rated at 44mpg highway. That is very efficient. However, 44mpg -> 53mpg is a 20% increase in distance per gallon of fuel. The Prius Prime is significantly more efficient. Since we're intentionally ignoring electric range in these numbers, I think the efficiency gains are mostly from the 9 years of R&D that passed between these two cars being built. Interestingly, the non-plugin 2021 Prius Eco is also rated at 53mpg highway. I do think it's odd that the extra weight from a larger battery didn't have a bigger impact on fuel economy. It looks like that makes a small difference in town, where the Prius Eco gets 58mpg vs the Prius Prime's 55mpg.

Panzer04 4y ago
Weight is not that important for highway driving especially, where the vast majority of resistance comes from air and not rolling resistance. It’s mostly bad for ICE stop and go, where you have to get the whole car moving again from a dead stop repeatedly.
ben7799 4y ago
The new Prius is probably larger & faster and meets more safety & emissions standards as well. And it will get much better fuel economy than the Civic as soon as traffic gets bad or some city driving is required. Picking highway MPG cherry picks the solution that makes the Hybrid or EV look the worst compared to the traditional ICE car. Not that the Civic is/was a bad car. But all cars are a lot bigger and safer than they were, so it's almost always cherry picking to go back and take an example of an old fuel efficient car. A lot of those old cars could not pass modern emissions or safety testing, they got their good fuel economy by being a) Slow b) Light. A big part of light was not having extra mass for safety or emissions. On top of all that the mileage ratings for cars have also changed, so you can't even directly compare the ratings for an old civic with a new one.
- unregistereddev 4y ago
  To be fair, the EPA changed the way they calculate mileage ratings in 2006 (affecting window stickers in 2008), so the 2012 Civic is a valid-ish comparison. Also, I chose the most efficient Civic available, which was the hybrid model. I do wholeheartedly agree with you, though. Even when cherry picking data (highway mpg's, ignoring miles driven in EV mode, choosing the most efficient Civic) and ignoring other factors (larger, safer, lower emissions), the Prius Prime is much more efficient. I think plugin hybrids have their place.
mabbo 4y ago
I'm gonna to be blunt: after reading more reviews, I picked a very poor car to use as my example of a bad PHEV. Prius prime actually sounds like a pretty solid vehicle. The general complaint that I hear about other PHEVs is that car manufacturers publish the "combined highway/ city" rating, which is weighted heavily in favor of city driving- which is where a PHEV is incredible thanks to regenerative braking. But if you're not using the brakes and just driving a long distance, your battery stops helping after 30-ish minutes and now you're just in a gas car with an undersized engine carrying a very heavy battery. Better to go pure EV instead, which is what I'm on a damned long waiting list to do right now.
- spiznnx 4y ago
  I really think you should test drive one. It doesn't have a huge battery and ice engine, it has a small battery and a small engine (at times frustratingly underpowered if out of battery). For short drives, the small battery saves you from hauling an extra 500 lbs of battery. For long drives a PHEV is still my preferred option over a BEV, because refueling every 300 miles is faster than recharging every 300 miles, and I'm not looking to have a spirited drive anyway.

Panzer04 4y ago

Weight is not that important for highway driving especially, where the vast majority of resistance comes from air and not rolling resistance. It’s mostly bad for ICE stop and go, where you have to get the whole car moving again from a dead stop repeatedly.

ben7799 4y ago

The new Prius is probably larger & faster and meets more safety & emissions standards as well. And it will get much better fuel economy than the Civic as soon as traffic gets bad or some city driving is required. Picking highway MPG cherry picks the solution that makes the Hybrid or EV look the worst compared to the traditional ICE car. Not that the Civic is/was a bad car. But all cars are a lot bigger and safer than they were, so it's almost always cherry picking to go back and take an example of an old fuel efficient car. A lot of those old cars could not pass modern emissions or safety testing, they got their good fuel economy by being a) Slow b) Light. A big part of light was not having extra mass for safety or emissions. On top of all that the mileage ratings for cars have also changed, so you can't even directly compare the ratings for an old civic with a new one.

unregistereddev 4y ago
To be fair, the EPA changed the way they calculate mileage ratings in 2006 (affecting window stickers in 2008), so the 2012 Civic is a valid-ish comparison. Also, I chose the most efficient Civic available, which was the hybrid model. I do wholeheartedly agree with you, though. Even when cherry picking data (highway mpg's, ignoring miles driven in EV mode, choosing the most efficient Civic) and ignoring other factors (larger, safer, lower emissions), the Prius Prime is much more efficient. I think plugin hybrids have their place.

mabbo 4y ago

I'm gonna to be blunt: after reading more reviews, I picked a very poor car to use as my example of a bad PHEV. Prius prime actually sounds like a pretty solid vehicle. The general complaint that I hear about other PHEVs is that car manufacturers publish the "combined highway/ city" rating, which is weighted heavily in favor of city driving- which is where a PHEV is incredible thanks to regenerative braking. But if you're not using the brakes and just driving a long distance, your battery stops helping after 30-ish minutes and now you're just in a gas car with an undersized engine carrying a very heavy battery. Better to go pure EV instead, which is what I'm on a damned long waiting list to do right now.

spiznnx 4y ago
I really think you should test drive one. It doesn't have a huge battery and ice engine, it has a small battery and a small engine (at times frustratingly underpowered if out of battery). For short drives, the small battery saves you from hauling an extra 500 lbs of battery. For long drives a PHEV is still my preferred option over a BEV, because refueling every 300 miles is faster than recharging every 300 miles, and I'm not looking to have a spirited drive anyway.