How to read plug-in hybrid specifications

As any politician (or plug-in hybrid car company) will tell you, you can always find a set of numbers to work in your favor, Ernst writes. The key to a wise plug-in hybrid purchase is doing your homework ahead of time, then basing your decision on the facts most relevant to you. 

A 2012 Chevrolet Volt electric vehicle is parked at the solar-powered electric charging station at General Motors Co's assembly plant in Hamtramck, Mich.

Rebecca Cook/Reuters/File

February 3, 2013

We’re going to let you in on a little insider’s secret: when manufacturers are shilling their wares, they tend to favor statistics that illustrate their own version of the truth.

As any politician (or car company) will tell you, you can always find a set of numbers to work in your favor.

Take the figures used by Toyota’s webpage to compare its Prius Plug-In against the Chevy Volt, for example. On the page, the Prius Plug-In is $7,200 cheaper, has more front headroom, more front leg room and features active head restraints unavailable on the 2012 Volt.

In the race to attract students, historically Black colleges sprint out front

These decisive victories are even marked by blue dots, lest the consumer remain unaware of the Prius Plug-In’s triumph over the Volt.

As My Chevy Volt points out, the facts aren't quite as cut and dried as Toyota would have you believe. The difference in price between the cars isn’t as significant as shown, since the Volt qualifies for a $7,500 tax credit, compared to the Prius Plug-In’s $2,500 credit. 

Put another way, when tax credits are applied, the price difference between the cars is just $2,200. That money buys you 38 miles of battery range on the Volt, compared to around 11 miles on the Prius Plug-In.

Even with a fully-charged battery, the Prius Plug-In needs to be driven as if you were hauling nitroglycerin. Accelerate with anything other than detached disinterest, and the Prius Plug-In fires up its gasoline engine, which also kicks in above 62 mph.

The Volt, on the other hand, can be driven like a conventional automobile on battery power, adding (in our opinion) to its appeal.

Moody chickens? Playful bumblebees? Science decodes the rich inner lives of animals.

In between these extremes likes the Ford CMAX Energi. It’s priced similarly to the Prius Plug-In, but it’s eligible for a $3,750 tax credit, making its list price the most attractive of the group.

It’s electric-only range of 21 miles (likely blended) bridges the gap between the Volt and Prius Plug-In as well, but like the Toyota the Ford’s engine will kick in under hard acceleration (or at speeds above 85 mph).

My Chevy Volt says the Ford CMAX Energi will cost 4.1 cents per mile (based on electricity priced at $0.12 per kWh), compared to 3.5 cents per mile on the Prius Plug-In and 4.2 cents per mile on the Chevy Volt.

Put another way, the Volt uses 35 kilowatt-hours per hundred miles, compared to 34 kW-hrs/100 miles on the Ford and 29 kW-hrs/100 miles on the Toyota.

Perhaps the most significant number to those saddled with long commutes is the extended-range mpg of each. Here, the Volt falls short, returning just 37 mpg to the Ford’s 43 mpg and the Toyota’s 50 mpg.

What does it all mean? Ultimately, the right choice of plug-in vehicle is dependent upon  your needs and driving style. If your round-trip daily commute is under 30 miles, the Volt will generally allow you to make the drive on battery power alone.

If you’re faced with a 110 mile daily drive like some of us here used to tackle, the Prius Plug-In or the Ford CMAX Energi would likely make a more economical choice. On the other hand, the Volt is the only one of the trio to use a liquid battery thermal management system.

As with any other major purchase, the key to happiness is doing your homework ahead of time, then basing your decision on the facts most relevant to you. Facts, that is, that you’ve obtained on your own, not from a manufacturer’s advertorial.