Most drivers waste a lot of gas sitting still with the engine idling. This happens in stop and go traffic, when you are at a red light, when you have to wait to make a left turn and when you are waiting at the curb to pick up your kids. It is hard or impractical to always manually switch your engine off and on in all of these circumstances. Engine technology is coming to the rescue, providing engines which automatically stop and restart when the vehicle idles. The tricky part is having the engine come back into action quickly. If you are waiting to make a left turn and your engine shuts off automatically to save on gas, then it has to restart when you stamp on the gas pedal. You want a speedy reaction ... maybe a short window of opportunity for your planned left turn opened up in the traffic flow. The Mazda 3 has a new system which supposedly allows for much faster restarts. That is very good news for saving on gas ... now we can stop burning gas uselessly while sitting still and drive off again quickly. Once again, note how it was not Detroit pioneering in this important fuel economy technology. Detroit's focus on short term profit from large vehicles blinded it to the coming reality of permanently high gas prices, and the result is the growing obsolescence of US automakers' products in the global market.