I would really like to see some facts of long term fuel and money savings. I know it would vary from driver to driver, but an average and potential numbers would be nice.

To help maximize what I believe would be the most effective way to get your "savings" (if any), and to try to prolong the life of the starter, driving with the auto stop/start has become an art for me.
If I'm approaching a traffic light that I know is going to change soon, I will brake a little sooner then coast to the light, rather than come to a complete stop for 10 seconds just for the engine to cut out and have to turn back on. If I see a light is turning red and staying red for 30 seconds or more, I will position myself so that when the engine shuts off, I wont have to move up a few feet which would fire up the engine again. Of course, familiarity with the traffic lights in your city helps. Today I went through the drive through at Tim Hortons to get a coffee and the line was moving slow. I was in line for about 6-8 minutes. So auto start/stop kicked on and *could've* been effective in saving me gas and releasing emissions into the air. Incidents like this *could* save money on gas but again I would like some numbers from a study.

 

So no price for the 2.7. And are there relays involved in the auto start/stop system leading to the starter that could have to be replaced as well? $$$$$

 

I didn't check every engine, but for your 2.7 the Motorcraft starter is $154 (Rock Auto again)

If your vehicle has the push button start I doubt any more electrical components are needed - it's nothing but software. Not sure about the keyed ignition, but probably not, just have to let the computer tap into the starter circuits?

 

Starter cost isn't out of line compared with a conventional starter. Thing is, I was led to believe they were beefed up and intended to take the abuse inherent in the start/stop/start feature. Is this not the case?

 

X2 on this, I have modified my driving to slow earlier and catch the change to green vs. sit at a short red. I also shut it off in stop and go traffic with those 2 or 3 second stops that trip the auto shutoff. It's an "overaggressive" system according to some.

 

There's nothing unusual about the starts, just probably an increased number of them. So what would beefed up require? Maybe heavier bearings, an upgraded bendix, larger brushes? That's relatively easy, and probably would explain the few dollars more. THe component I'd most worry about would be the ring gear - definitely the most expensive part of the system to replace.

 

I don't know what the duty cycle for an engine starter is exactly. Probably several minutes for every 10 seconds cranking. Normally an engine starts in just a split second. Then it's not needed again for a while. That's how a relatively small electric motor can crank a big heavy duty engine over in the first place without burning up, it's only required to do so for a very short while. Same thing with solenoids. But start wailing on them, or over and over, and they will soon fail. Maybe not the next day, but they are not going to be around long.

Typically abused starters just don't last, when they get hot the windings start roasting the insulation off, among other things. And that's OEM. The rebuilds are always a crapshoot these days. I assume that the starters here would need to be designed for a higher rated duty cycle. Same thing with starter solenoids or relays. You can buy continuous rated solenoids, but they cost ten times what the cheapies cost.

 

Good points. I think the life of a starter in these systems is going to dependent on the specific usage. The start/stop software obviously has no idea how long the vehicle ill be stopped, so extreme stop and go traffic situations could easily overheat the starter - and drain the battery. Yet the computer systems in these vehicles seems to be pretty smart, it's possible that the recent duty cycle is being monitored and if a threshold is reached, the start/stop is temporarily disabled? Or if the battery is being discharged too rapidly? Or...? That's all total conjecture on my part, but I'd actually be surprised if that type of monitoring and action *wasn't* being done. With all the sensors and monitoring that's done already, adding features like that is just software, which is very little added cost.