Edge ST with performance brakes spare tire

[taurussvt]

I know that when you get the performance brake package on the ST it doesn't come with a spare tire, but has anyone actually tried the 18" spare to see if it will fit over the brakes?

Reason I'm asking, besides the spare tire kit being over $200, is that I recently had an 18" Ford wheel NOT fit over my front brakes. It was a 2018 Focus ST wheel. I'd assumed it would fit since the earlier snowflake Focus ST wheels which are also 18" fit. So before laying out the money for a spare tire kit, I'd like to know if anyone else has tried this and what the result was.

[dabangsta]

I hope you get a reply from someone that has tried it and not just speculating (like me...).

 

I want to upgrade my front brakes on my FWD 2019 SEL to the larger AWD rotor and calipers. The rotors are the same size as the ST/ST Performance (345mm...and are 25mm larger than the Focus ST...) and I need to upgrade my 17 inch spare to 18 inch. Other than the calipers have 2mm larger pistons (than the standard brakes) and painted, I don't think there is that much difference in the size. More the difference in the rotor style.

 

The order guide says that the inflator kit is substituted due to the summer tires, and not the brakes.

Edited December 20, 2023 by dabangsta

[taurussvt]

I've got the order guide for 2021 open on my computer and see where it says Includes Tire Inflator and Sealant Kit with the Summer Only Tires under the 401A option. 

It still makes me nervous ordering that kit though. 

Edited December 20, 2023 by taurussvt

[taurussvt]

I decided to bite the bullet and buy the spare tire and tool kit. I just confirmed that the wheel fits over the brakes with plenty of space, over a 1/4” between the calipers and the wheel. 

[taurussvt]

I know it’s not that easy to tell because of the shadows and whatnot, but there’s about a 1/4” of space between the caliper and the inside of the front wheel.

 

 

This is on the rear, and there is even more room than the front. 

Edited January 28 by 1004ron

[dabangsta]

Thanks for adding the images! I would have thought the rears would be less gap as the EPB usually causes more clearance issues on other vehicles.

Unrelated to the spare fitment with ST Performance brakes mostly, I have debated going further than just the larger front rotors (I think FWD and AWD use the same caliper and pads, but a different caliper mount, which seems like the radius of the pads would be odd) and possibly going for the 345mm rotors all around, with the brake calipers in the front with the larger pistons. I don't think it would affect things like the adaptive cruise or emergency braking (it doesn't just blindly apply brakes, it could tell that it might be stopping better and lower the effort).

 

I just don't think I drive the vehicle enough around town to do the work. It is my wife's daily driver, I generally only drive it on the highway on vacations. Should doesn't think it needs new brakes, let alone better ones, and she is really not into red painted calipers. The brakes it has are more than adequate for daily driving and panic braking. I tend to get them to fade most times I drive so I usually have to replace them more frequently and also usually try to do OEM style upgrades (like 13 inch Cobra rotors to replace 10.8 inch rotors on my Lincoln Mark VIII).

[STBEAST]

Just wondering, can you use a smaller diameter tire as a spare. I know on some vehicles it can damage the all-wheel drive system and you have to use the same diameter tire as a spare.  ????

[omar302]

13 hours ago, STBEAST said:

Just wondering, can you use a smaller diameter tire as a spare. I know on some vehicles it can damage the all-wheel drive system and you have to use the same diameter tire as a spare.  ????

 

The stock compact spare tire is smaller in diameter than the regular wheels/tires and it causes the AWD to disconnect. It defaults to FWD only.

 

From the owners manual:

 

Quote

Do not use a spare tire of a different size other than the tire provided. If the mini-spare tire is installed, the AWD system may disable automatically and enter front-wheel drive only mode to protect driveline components. A warning in the information display appears, indicating that the system is in front-wheel drive only mode. See Information Messages. If there is a warning message in the information display from using the spare tire, this indicator should turn off after reinstalling the repaired or replaced normal road tire and cycling the ignition off and on. We recommend that you reinstall the repaired or replaced road tire as soon as possible. Major dissimilar tire sizes between the front and rear axles could cause the AWD system to stop functioning and default to front-wheel drive or damage the AWD system.

 

[1004ron]

Thanks for that omar302

 

I would be concerned for the front differential and would limit the distance as best possible using the smaller diameter spare on the front, and the same goes for the rear.

 

I can see the reason to disable the AWD because the wheel speed sensors would make it appear that one wheel is slipping, but my concern is the two differentials whenever there's an odd sized wheel used.

Edited January 29 by 1004ron

[omar302]

3 hours ago, 1004ron said:

but my concern is the two differentials whenever there's an odd sized wheel used.

 

I would be less concerned with the differentials as they are open diffs, they are routinely rotating at different speeds any time the car is not going straight ahead.

 

The PTU is a straight gear link, and hence cannot tolerate any rotational speed difference between both sides, hence the clutch pack that engages/disengages when needed, not only for traction, but to also prevent binding between front and read on hard turns.