The EPA has recently revamped their fuel economy ratings. The old tests were criticized for being outdated and just not very good at measuring what people were getting in 'real world' driving conditions. So, in 2008, all new vehicles will be rated using this new system.
The big question is, how are these new ratings going to affect hybrid cars? Most analysts predicted hybrids would be hit harder than other car segments. But first, let's see what the EPA has changed about their rating system.
The new rating system takes into account
- Faster Speeds and Acceleration
- Air Conditioner Use
- Colder Outside Temperatures
- wind and
- road surface resistance.
When I looked at how the new ratings would be applied to hybrid cars, I saw a 10% to 18% drop in fuel economy ratings (See table at the end of this post for New EPA MPG Estimates on 2007 Hybrids). This rate of change seems to be consistent whether you are talking about full hybrids or mild hybrids. Although, it's interesting to note the two cars with the most to lose (Prius and Civic Hybrid) did drop the most percentage-wise.
But, it seems that most cars are seeing about that much change. As you can see, I looked up the Toyota Corolla and Camry (non-hybrid, automatic, 4 cylinder), and both cars dropped 12% and 11%, respectively. According to GreenCarCongress, all cars will see some drop in their ratings, from 8% to 30%
Compared to today’s estimates, the city mpg estimates for the manufacturers of most vehicles will drop by about 12% on average, and by as much as 30% for some vehicles. The highway mpg estimates will drop on average by about 8%, and by as much as 25% for some vehicles.But it looks like hybrid cars can still claim top position, especially over their conventional counterparts (gas only, same type), which are seeing just as big a drop, percentage-wise. The fuel economy improvement is slightly lower than it used to be, but that difference really is slight.
One other thing to keep in mind. Despite the drop in ratings to indicate a more 'real world' estimate, individuals are still going to see their mileage vary from these ratings. Some will continue to see higher (see hypermilers), while others will see lower (see your 16 year old cousin who just got his/her license).
|New EPA MPG Estimates on 2007 Full Hybrids|
|Make||Model||Old/ New||City ||Hwy|| Combined ||% Dropped|
|Toyota||Highlander Hybrid 2WD||Old||32||27||29||10%|
|Toyota||Highlander Hybrid 4WD||Old||31||27||29||10%|
|Ford||Escape Hybrid 4WD||Old||32||29||31||13%|
|Ford||Escape Hybrid FWD||Old||36||31||34||12%|
|Lexus||RX 400h 2WD||Old||32||27||29||10%|
|Lexus||RX 400h 4WD||Old||31||27||29||10%|
|Mercury||Mariner Hybrid 4WD||Old||32||29||31||13%|
|Chevy||Silverado Class 15 Hybrid 2WD||Old||18||21||19||11%|
|Chevy||Silverado Class 15 Hybrid 4WD||Old||17||19||18||11%|
|Toyota||Corolla (Automatic, 4 Cyl)||Old||30||38||33||12%|
|Toyota||Camry (Automatic, 4 Cyl)||Old||24||33||27||11%|