Wednesday, 11 June 2008 12:00 AM
Environmental website Clean Green Cars has released figures showing current hybrid cars offer no significant CO2 advantage over an equivalent diesel of similar performance.
The site tested three hybrids and three diesel models under the same conditions, with the fuel consumption figures showing that the diesel cars used less in general.
Therefore, it was posited they also emitted less CO2.
The tests involved a return trip from central London to Brighton, taking in a mix of urban, dual carriageway and motorway driving.
Jay Nagley, publisher of Clean Green Cars, said: "People may be surprised to learn that hybrids are no better in the real world than diesels, but our tests confirmed what we had long suspected.
"Hybrid technology offers the prospect of real benefits, but only with the next generation of plug-in hybrids using more advanced lithium-ion batteries, which are expected from 2010. Current models only confer dinner-party bragging rights."
Hybrids became popular in the US because they are the only alternative to conventional petrol engines - diesel passenger cars are virtually unknown in the United States.
Hybrids generally spend almost no time driving on battery power alone, with the exception of some Lexus models.
Hybrids have traditionally had an advantage because the engine does not usually idle at traffic lights, for example. However, with stop-start technology on a lot of modern diesels, this is no longer the case.
Indeed, if the batteries run down, a hybrid will automatically start the petrol engine at lights just to recharge the batteries.
"We are not anti-hybrids," Richard Bremner, editor of Clean Green Cars commented. "The concept offers the prospect of genuine fuel saving with models promised from 2010 that will drive up to 40 miles on electric charge.
"However, today's models using current battery technology offer no real environmental benefits for British drivers. For your next new car, we would generally recommend an economical conventional engine - for the one after that a hybrid may make sense."
The results of the efficiency tests were as follows:
Toyota Prius vs. Jeep Patriot 2.0 CRD
- Toyota Prius: 39.9 mpg
- Jeep Patriot: 38.9 mpg
Honda Civic vs. Ford Focus Econetic
- Honda Civic IMA: 40.2 mpg
- Ford Focus Econetic: 52.7 mpg
Lexus GS450h vs. BMW 535d
- Lexus GS 450h: 28.5 mpg
- BMW 535d: 30.6 mpg