However, its use is contentious for many carmakers as the U.S. EPA official fuel economy figures are completely unaffected, even if there are gains to be had in the real world - from 3-5 percent.
Kia is the latest maker to adopt the technology and the best news for drivers on a budget is that it'll be available on the new 2012 Kia Rio. Like the old Rio, it's one of America's cheapest cars at only $14,350, but unlike the old Rio it's a sharp looker and should make a splash at the bottom of the market.
Stop-start has been available on more expensive vehicles for a while now but Kia's system brings it to the bottom of the market. It's technologically quite simple - with only around six parts - and will be relatively inexpensive too, at $400 as part of an Eco package.
Speaking with USA Today, Steve Kosowski from Kia says the new Rio will have the same EPA figures as the Hyundai Accent (30 city, 40 highway), but in the real world drivers will see more of a fuel saving.
All this is good news for drivers on a budget. As fuel-saving technology appears lower down the market, it proves you don't necessarily need to spend another ten thousand on a hybrid to save a tiny bit of money on gas.