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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!!!
 

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Discussion Starter · #22 ·
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?
 

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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.
 

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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?
That might be normal. If you sit in the car for a while after turning it off it makes all kinds of sounds. At least one of them is it opening and closing the exhaust flap, but there's also whirring and popping noises. I have no idea what all of them are! Definitely freaks everyone out who's ever sat in my car for long enough
 

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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.
 

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Atom - my thoughts on Start/Stop

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

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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.
 

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That might be normal. If you sit in the car for a while after turning it off it makes all kinds of sounds. At least one of them is it opening and closing the exhaust flap, but there's also whirring and popping noises. I have no idea what all of them are! Definitely freaks everyone out who's ever sat in my car for long enough
I actually love this about the car.

Makes me feel it's alive or something.
 

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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.
 

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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.


Sent from my iPhone using Tapatalk
 

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This car should have never come with auto start/stop to begin with, period.
Disagree, its completely useful and I do see a gas savings benefit from it. I usually disable it for the first few minutes of driving in the morning so the engine warms up, but once the engine is warm I let it shut off as it pleases.

As for is it possible to get 20mpg+? 100% possible. Your daily commute and driving habits will have the biggest impact on fuel economy. But you can see what's possible below.


I log every single fill up in Fuelly, and I often export the data into a Google Sheet so I can manipulate it how I want.

In March of 2020 I made a change to my driving habits. I put a leash on my highway speeds and started using cruise control on the highway set to 65mph. You can see in March of 2020 the immediate and dramatic impact it had on my fuel economy.


351567
 

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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.
Incorrect.

Any statements about Engine Wear are almost exclusively regarding a cold engine that has been sitting overnight. At that point you are relying on the left over oil film on the bearings to lubricate the system before you get some oil flow. In extremely cold weather it can take up to 15 seconds to get oil to the turbo. Literally 1-2 ignition cycles with the gas fully depressed to disable the injectors.

For a warm engine the argument is a throw-away. Hot oil pumps easily, the engine was just running minutes ago at most, and everything has a very fresh coating of oil. Idling vs starting a warm engine is a wash in terms of engine wear.
 

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Disagree, its completely useful and I do see a gas savings benefit from it. I usually disable it for the first few minutes of driving in the morning so the engine warms up, but once the engine is warm I let it shut off as it pleases.

As for is it possible to get 20mpg+? 100% possible. Your daily commute and driving habits will have the biggest impact on fuel economy. But you can see what's possible below.


I log every single fill up in Fuelly, and I often export the data into a Google Sheet so I can manipulate it how I want.

In March of 2020 I made a change to my driving habits. I put a leash on my highway speeds and started using cruise control on the highway set to 65mph. You can see in March of 2020 the immediate and dramatic impact it had on my fuel economy.


View attachment 351567
I can vouch for your experiment.
I actually used cruise control on a trip to Rotterdam and did not exceed 2000 rpm for a few hours.
The car had the best mpg I have ever seen but my life has never been so boring. I think watching paint dry would have been more entertaining. Coming back I tanked twice but it was fun as hell.
 

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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?
 

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Incorrect.

Any statements about Engine Wear are almost exclusively regarding a cold engine that has been sitting overnight.

For a warm engine the argument is a throw-away. Hot oil pumps easily, the engine was just running minutes ago at most, and everything has a very fresh coating of oil. Idling vs starting a warm engine is a wash in terms of engine wear.
I suppose.

I'm interested to hear your thoughts on the other points.. strain on the electrical system and battery, the starter, the timing chain and drive belt and all the accessories, and the motor mounts too, due to the excessive amount of start/stop cycles?
 

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I suppose.

I'm interested to hear your thoughts on the other points.. strain on the electrical system and battery, the starter, the timing chain and drive belt and all the accessories, and the motor mounts too, due to the excessive amount of start/stop cycles?
You apply more torque on a shift than the engine experiences in a start/stop cycle. Consider how much torque gets applied to the engine when you slam on the brakes while in gear, or mat the throttle after an upshift.

When starting an engine its disconnected from the driveline, so aside from the inertia of the rotating assembly, its not really acting against anything. When you take off from a stop, the engine now has to move 3450lbs+ driver.

The battery does see more wear, but Ford also opted for a larger battery size than they would have before. The battery has 760cca, and 950ca. The 11:1 compression V8 in my GTA uses a 650cca battery and cranks just fine.

Starters are really pretty low power honestly. Lets take the worst case scenario. We can easily estimate how much HP is drawn. 745 watts = 1hp. And Watts = Volts * Amps.

950 * 12 / 145 = 15hp. Sure, its at a very low RPM. Starters now are usually gear reduction, but still spin the engine around 200rpm. With a known RPM we can turn HP into torque. Worst case scenario at max current draw of 950 amps, we are looking at about probably 400lb/ft. However, a hot 4 cylinder only needs about 150lb/ft to turn over. And being that we are a turbo car, our static compression is lower, so its easier to turn the engine over.
 
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