Battery might the cause of the auto start stop. Mine stopped working after 2.5 yrs of owning.

 

Def battery. Mine did the same.

I’m tempted to put an old battery back in just to disable it.

 

So if the battery reaches a certain level the auto start stop is disabled? When I come to a stop, the icon appears on the display but it’s greyed out of that means anything?

 

If you read the manual, it states that certain conditions have to be met for it to work, engine temp, ac level are a couple of things that come to memory regarding this. And if you battery is on its way out, it won't work also.
But as others have said, this has been turned off on mine from the get go, if you have a Cobb AP you can switch it off with that too.

 

This car should have never come with auto start/stop to begin with, period.

 

This! First thing I had my tuner do was disable it. Cars have been manufactured for years without it. I'd rather save my battery life.

 

You can add the multi-color lights from the lesser model as well btw. I have most of the PNs if desired.

 

Good to know, would the infotainment system need any updating to accomodate or is it all the same?

 

I'm one of the minority RS owners who also enjoys the start/stop. You need to check your battery age, because it will not activate if your battery is too old (or the car thinks it's too old). My car had it's battery replaced about 3 months before I bought it, but battery age was not reset. Once I used Forscan to reset it suddenly the start/stop was happening at every stop.

My opinion is if my engine doesn't need to be running, why should it be? I've saved several minutes of wear on my engine at a time. While some may argue the start/stop cycle causes more wear than just running it, I think an at-operating temp engine can handle a start/stop cycle with less wear than keeping it running. By now you also realized I'm OCD and somehow the start/stop satisfies that lol.

Fords reason is obviously for emissions, as the RS is an emissions pig so by adding this ridiculous feature for a performance car they save that much more money with emissions penalties. It makes zero sense for the RS to have it, that I can agree with, but I'm also glad they added it for my personal preference.

 

I'm one of the minority RS owners who also enjoys the start/stop.

My opinion is if my engine doesn't need to be running, why should it be? I've saved several minutes of wear on my engine at a time. While some may argue the start/stop cycle causes more wear than just running it, I think an at-operating temp engine can handle a start/stop cycle with less wear than keeping it running.

I think starting an engine is the most abusive time for an engine under normal operating conditions. Starting a warm engine might be less abusive than starting a cold engine as the warm oil will reach sensitive bits sooner. Still, these are the two most abusive times for an engine under normal operating conditions (zero oil pressure), from what I understand. I def could be missing something?

Engine wear due to running at a stoplight for some length of time I think most people would consider to be negligible. Stopping and starting an engine during these times would not only wear the internals unnecessarily, but also apply additional strain to the electrical system and battery, the starter, as well as the timing chain and accessory belt.

 

I have not seen MPG drop blow 21 on my car. I have averaged 21-23 between each fill up with mostly in the 22. And all of this is city use and have never taken it on a road trip. And yes, start/stop stopped working for me a year back. I have to admit, it was annoying.

 

Clearly you aren't driving your car IMO. Only time I average anything over 20 is highways/open roads.

 

One of the conditions that Auto Start/Stop gets disabled under is Battery State of Charge (SOC) below 69%. Our cars sat around for months during the process of building and getting them to our dealers. Then, once the initial demand was satisfied, many sat on dealer lots for many additional months before they were purchased. All of this reduced the battery's capacity to hold a charge. It was not surprising when AS/S stopped working and owner's started reporting other odd electrical issues. And now we are seeing batteries getting replaced but the battery status not getting reset.

 

Auto start- Hardly ever worked for me, disabled it asap.
Color- Thought the same thing coming from an ST3
Cupholders- Same as above. Had them, but not in the RS. Good excuse for my nephew to not get soda at the gas stations lmao
MPG- I do really well on the highway, terrible in the city. ~21-22mpg for me, but on a long trip I've gotten 26mpg over like 3500 miles.

 

I think your battery is still fine, it just does not meet the parameters to do auto start stop.

 

I guess I’ve been hardwired since I was a little kid, steering from my Dad’s lap, (don’t try that today) if your car stops at a light..you’ve got a problem!

 

Good gas mileage depends on a little bit of discipline and properly managing your car's energy. Steady state cruising at an appropriate RPM, accelerate on downhills if you can, go the speed limit, and take advantage of the auto stop/start if you can get it working. You'll have no problem clearing 20 miles per gallon even in the city. My average down in Portland was around 23mpg around town.

 

Regarding battery, you might start seeing electrical gremlins. I first lost Start/Stop, but thought nothing of it. Eventually I started getting weird situations where I would turn off my car and it would go dead-dead instead of the typical shutting down process like some kind of controller just died. Dealership was useless in trying to diagnose it because they kept trying to replicate it - which is unlikely to happen because that's the nature of intermittent issues. I was told they could not reach out to Ford engineering either without repro - even though the service tech literally saw it happen when I dropped the car off. Swapping the battery on recommendation of forum users solved the problem.

Anyway, bitching aside, if you start seeing gremlins, don't panic - it might be your battery.

 

Speaking of gremlins. I forgot to mention earlier about the clicking sounds I always hear after the car is unlocked prior to getting in? And then when the car is shut off and sits after 5-10 min it will start making more clicking sounds with the temp and fuel gauge needles twitching. I'm guessing it the fuel pump after unlocking?

 

Honestly I don't think the focus is that bad. I average 12 litres per 100 km on hard driving. I see 14!, but average around 9-10l/100 km and get around 320 kms pertank. My son's 15 year old Subaru 2.0 impreza is worst!!!

 

Auto Start/Stop stopped working a long time ago for me. Most likely due to battery condition. I’m glad it turned off on it’s own. The hesitation at when trying to get going after a light turns green was annoying.

As for mpg, I average 20.7-21 with 100% city driving. I’m Definitely not driving it gingerly. Of course with traffic I can’t do much but when the road opens up, so does my throttle lol.

 

I drive pretty enthusiastically too, and I usually average around 20.5 to 21.5 mpg per tank, assuming I’m not sitting in a lot of traffic. On the highway, I usually only see 24 mpg.

 

24 is really good! I don't even get that on the highway. I am tuned and will bring it up on my next tune.

 

Atom - my thoughts on Start/Stop

Battery use
Starter use
Flywheel teeth
Running = oil pressure
Running = oil and coolant runs thru turbo

 

I have all those thoughts as well, and the answer I use is "this was engineered to handle the additional stressors"

This article hits a lot of those concerns nicely, but even they agree nobody really knows for sure: Does Auto-Stop/Start Technology Wear Out Engine Components?

 

Will chk out. I'm old school and don't trust many ppl including the policies that force the engineers to follow a corporate structure on price points. Not to mention most of us have modded engines which is out of their engineered scope of heat and stress. That's why re: trust, I and most of "us" do our own work from oil to full builds. Would love to see your results of what I sited after 200k miles. I'll most likely still be here.

 

lol we're off topic so I'll leave it there.

 

Hhhmmm. Noticed at fill up today I averaged 25.1 mpg with some spirited driving since my FoST ate a part of my K&N filter, seizing the turbo earlier in the week. (Yay! New turbo for my daily driver) Finally made it past 22k in the FoRS and 97k in the FoST. Full synthetic oil in both and pure 93 octane FTW. Happy with both cars.


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Are you getting the same/similar MPG from both cars?

When I drove my bro’s FoST for a week while waiting for the RS, I got 23 mpg.

After 4 weeks and 1k miles in the RS, I’m getting 23 mpg. I was expecting it to be at 20 or below so I'm a bit surprised.

 

It's a performance hot hatch, I don't think people buy this to save on fuel. Even if you do like the little bit of fuel savings it gives you, it's still going to stop working after a couple of years of beating on the battery. I also don't like that slight hesitation of the engine having to start up again. I don't even think it's competitors have this feature, do they?

 

Hate the auto stop start

 

I hate not having a FoRS so I can hate having the AS/S

 

A button press turns it off. Not a big deal.

It's muscle memory for me when I get in. Start button, auto stop/start button, drive mode, two right arrow clicks, OK button, damper setting button. I'm ready to drive. Unless my door is open, then the god damned "engine on" and "door open" messages **** up my flow.

 

I took my RS for a short road trip and finally got see 22mpg on the road. I have 70 miles left on the tank and if i keep it up i might see a 21mpg avg for the first time on my next fillup. It's funny how your projected mileage on refuel is based on your final avg.

BTW, is it normal for the front brakes to squeal during a light pedal press in reverse?