Visit any European city, and you'll be struck by an unfamiliar sound: That of engines, previously silent, re-starting on every green light.
A large number of cars in Europe now feature stop-start technology as standard, and while EPA mileage figures aren't favorable to its effects, they're starting to appear in the U.S. too.
People do have concerns over just how many restarts the systems can handle, but one firm is now guaranteeing its systems for 1.2 million restarts.
UK-based Controlled Power Technologies, or CPT, says its SpeedStart belt-integrated starter-generator system has seen two years of development and is confident it can handle 1.2 million stop-start cycles, the highest in the industry.
The systems handled as many as 7,200 restarts every day over the course of a year, with engine-off periods lasting between 5 and 25 seconds.
With that sort of longevity, the case for stop-start becomes much stronger.
More durable than regular starters?
Not that it isn't with current systems--which can comfortably handle between 150,000 to 300,000 stop-starts, mandated by OEMs.
By comparison, the humble starter motor is typically good for around 30,000 cycles. The extra longevity of start-stop systems is thanks to heavier-duty components, specifically designed to stop and restart thousands of times--in the knowledge that such systems will work dozens of times a journey, in many cases.
The high mileages modern vehicles are designed for mean components such as starter systems must last longer as well. CPT says modern cars can easily see 250,000 miles in 15 years nowadays, and future technologies may see them worked even harder.
One of these CPT expects to see is engine-off coasting--stopping at highway speeds under zero load--in regular, non-hybrid vehicles. In such scenarios, an engine may stop and restart hundreds of times in a journey, and a fast re-start is vital to ensure a driver can accelerate at any time.
Product group manager Peter Scanes said of CPT's system, "We needed therefore to demonstrate as convincingly as possible the near-zero probability of failure during the lifespan of a vehicle as well as the ability to achieve the maximum number of re-starts.
Controlled Power Technologies' stop-start system
"One of the most cost effective solutions for low fuel consumption is simply stopping the engine at every single opportunity – even if it’s only for a few seconds every stop counts" he adds.
Impressively, CPT also says its systems are effectively 100 percent recyclable at end-of-life--with only steel, copper, aluminum, some plastics and silicon used in their construction.
Several carmakers are already interested in the technology, and the company says the first vehicles with its system will appear by 2015.
Stop-start may not show benefits on the EPA's window stickers, but in heavy traffic--and now, over the course of a car's life--they're the more durable, gas-saving option.