ideutsch

I've recently placed an order for a 2019 RC 350 F Sport RWD to replace my 2015 IS 350 F Sport RWD and I'm trying to determine the best option for all-season tires as this will be my daily driver. Unfortunately, the original equipment tire sizes do not line up with any direct-fit all-season tire options. I'm interested in hearing advice from others who have more experience with this.

The average winter temperatures (Dec, Jan, Feb) here in Oklahoma range from 30 to 50 degrees and occasionally dip into the teens, which can be quite sporty with summer tires. I know the low temperatures can also damage the summer tire compound. I've considered swapping to winter tires during the cold months, but that seems like overkill for the few days of bad weather we may get. There are also the random warm weather days during the winter, which aren't great for winter tires either.

Original equipment tire specs are:
Front 235/40R19 96Y
Rear 265/35R19 94Y

I've come up with two options:

Plus zero sizing -
Michelin Pilot Sport A/S 3+
Front 245/40R19 98Y
Rear 275/35R19 96Y

Mismatched speed rating -
Goodyear Eagle F1 Asymmetric All-Season (possibly identical to Dunlop Signature HP)
Front 235/40R19 96W
Rear 265/35R19 94Y

I've read that having mismatched speed ratings can cause unpredictable handling characteristics. So, I'm leaning towards using the plus zero sizing, for which the diameter is 1.19% off for the front and 1.05% off for the rear.

Can the Revs/Mile be adjusted with Techstream?

I don't think there will be a fitment issue, but has anyone used the sizes I'm considering with the factory wheels?

15RC350F

Note: no "tech questions" - I'm no expert. I was, though, told not to worry about the speed ratings unless I'm going to drive over 100MPH. I'm not.

I have the following, bought from Tire Rack and installed locally:
235/40R-19 GOODYEAR EAGLE F1 ASYMMETRIC ALL-SEASON XL
265/35ZR-19 GOODYEAR EAGLE F1 ASYMMETRIC ALL-SEASON

The ride is responsive, and quieter than (what I thought were) the horrible stock ones, but still with good road feel. MUCH longer tread life as well.

gkcmilner

Yokohama Advan Sport A/S 235/40r19 and 265/35r19 at tires.com
Had them on my BMW and was pleased with their well rounded performance. If I keep the RC I'll get these.

ideutsch

ZAM

Just an update, but I put Michelin Pilot Sport A/S 3+ Front 245/40R19 98Y and Rear 275/35R19 96Y on my RWD RC last week and they are fantastic. The stock dunlop summer tires were awful and the all-seasons are perfect for OK. I feel like our cars can really take advantage of the wider tires too.

ideutsch

ZAM

I still need to put more miles on it to break them in (break in is around 500 miles) to see their limit but in comparison to the stock Dunlops they are much more comfortable and feels like they handle a lot better. These are a direct fit to the stock 19 inch wheels and my tire store had zero problems mounting them. I did not adjust speedometer calibration because after I did some research I found that the difference is very minimal. The steering actually feels better which is weird since they are slightly wider, which is probably due to the tires being better suited for the temp range in OK. The tires have zero problem with the fenders through the full range of motion. I also stuck with the stock tire pressures after I did some research. Overall, I think these are the best all-seasons for the car and even Tirerack seems to agree.

ideutsch

Just wanted to follow-up on this. I had the following tires mounted last week:

Michelin Pilot Sport A/S 3+
Front 245/40R19 98Y
Rear 275/35R19 96Y

They are quieter, grippier, and cheaper than the OEM while being all-season. There is a marked improvement in the ride quality with these tires and there are no issues with tire fitment or speedometer readings (I compared GPS speed to the speedometer at 80+ mph).

S2KBobby

Have you noticed a difference in road noise with the new tires? Michelins can sometimes be noisier tires, depending on the style.

ideutsch

I find them to be quieter than the stock Dunlop on the roads I travel, though I should mention that these tires are not broken in yet. The ride is more comfortable and concrete highways with rough breaks between slabs are also quieter than before.