Non-RFT = mushy feel ?

[socalengineer]

Hi All,

In the past I had ditched the runflat oem Dunlop tires for a set of Hankook Ventus V12 Evo's, and to be honest because of the sidewall differences the car felt extremely mushy. It's almost as if the suspension of the car became too soft and I had no road feel anymore.

My question is was it because I didn't choose a good tire? Most everyone else here has upgraded to the Michelin Pilot Sport 4S tires. All of the searches I have done show everyone is extremely happy with that tire. But that wasn't my experience with the Hankook's and I immediately returned them for a rft. Maybe the Hankook's don't have a great sidewall? They get very good reviews for a budget performance tire.

I know BMW claims to have tuned the suspension for RFT tires on these cars, does that mean softer springs? I do plan on going with the Bilsten B12 Pro-Kit which has 10-15% stiffer springs, and stiffer dampening shocks. Is the stock suspension too soft for non-RFT tires?

Thanks everyone for your opinions!

[Wanwansuii]

I just bought my Gran Coupe 3 months ago, and it is currently riding on Continentals. Before purchasing this one, I did test drive another Gran that had Dunlops (not sure if RFT or not), and I do recall that there was a bit more road feel than the Gran I purchased. It actually felt pretty close to my old E92 M-sport coupe, which had a stiff yet "more traditional" BMW driving feel and ride.

I have heard good things about the Michelin Pilot Sports (my dad has them on his F10), and the car rode much better than the stock RFTs.

I would say try the non-RFT Dunlops (which in my experience are the stiffest compared to Michelin and Continental, and would work best if you want the most road feel; I have no experience with Hankook) or the Michelin Pilots, which are generally well-liked across the BMW range.

But keep in mind that our 6 platform, while it has a fantastic and smooth ride, has had several complaints with not taking certain (even small) road potholes or bad road imperfections well, especially compared to the F10. I can attest to this as I have driven over some road imperfections here in California and was surprised at how harsh it felt in the cabin (not all the time but every now and then). Surprisingly, my car takes road imperfections better in Sport mode rather than in Comfort. Quite a weird quirk..

[Wanwansuii]

I also have noticed that tire pressure, even the slightest change, makes a big difference in ride compliance and road feel. I usually up the tire pressure by 2 PSI on all four tires to slightly increase the road feel and decrease the "mush".

[Qsilver7]

Originally Posted by Wanwansuii

... Before purchasing this one, I did test drive another Gran that had Dunlops (not sure if RFT or not), and I do recall that there was a bit more road feel than the Gran I purchased. It actually felt pretty close to my old E92 M-sport coupe, which had a stiff yet "more traditional" BMW driving feel and ride....

Was that car AWD (ix)? The RWD models have EPS (electronic power steering) unless you have one of the adaptive suspension options...whereas the AWD models have a PS reservoir filled with hydraulic fluid that assists the EPS. I've found that the AWD (ix) models do have something much closer to the old time BMW "feel".

My 650ix GC has the hydraulic PS fluid reservoir where as my f15 X5 only has EPS...and the comfort mode in the 6 series is tighter/stiffer than the sport mode in the X5.

[Wanwansuii]

They were the same exact RWD model, only a year difference (2015 vs 2014). I have driven my dad’s F10 xDrive, and that felt even closer to the old school BMW feel with the hydraulic steering system.

Too bad the RWD models don’t have EPS; it would really do them justice.

[Derekz4]

The Hankooks sidewalls are very weak IMO. I have a set on my Mazda3 and had the same issue after I switched from the Yokohama tires that came with the car. And that was just switching non runflat tires. I can imagine the difference between a runflat and the Hankooks would be huge.

[Parksie11]

I've used Hankooks on my last 3 cars, they are brilliant, maybe change your tire pressures/.

[ACS650GranCoupe]

I also replaced all my Dunlops RFT w/ Michelin PS4S and they feel much smoother. I still feel that mushiness that you are talking about though with proper tire pressures (on the high side for me).

[socalengineer]

Originally Posted by ACS650GranCoupe

I also replaced all my Dunlops RFT w/ Michelin PS4S and they feel much smoother. I still feel that mushiness that you are talking about though with proper tire pressures (on the high side for me).

Are you lowered? Or stock suspension?

[TON-III]

Suspension is to be counted as a whole where springs, shocks and tires with non suspensioned weight all affects. RF tires are accurate to the road and too accurate may I say when a pothole occurs so it hits quite badly to the chassi too. I've managed to please me with choosing progressive spring, quite tough shocks, low weight rate non RF tires ( with low weight, too). It's true that it might feel a bit soft when cornering but is it the CASE with luxurious car which is driven 99,8% straight ?

My tires are now Goodyear F1 Asymmetric 5, much more nice and comfortable than Hankook's which were taken away.

[city1991]

Originally Posted by socalengineer

Hi All,

In the past I had ditched the runflat oem Dunlop tires for a set of Hankook Ventus V12 Evo's, and to be honest because of the sidewall differences the car felt extremely mushy. It's almost as if the suspension of the car became too soft and I had no road feel anymore.

My question is was it because I didn't choose a good tire? Most everyone else here has upgraded to the Michelin Pilot Sport 4S tires. All of the searches I have done show everyone is extremely happy with that tire. But that wasn't my experience with the Hankook's and I immediately returned them for a rft. Maybe the Hankook's don't have a great sidewall? They get very good reviews for a budget performance tire.

I know BMW claims to have tuned the suspension for RFT tires on these cars, does that mean softer springs? I do plan on going with the Bilsten B12 Pro-Kit which has 10-15% stiffer springs, and stiffer dampening shocks. Is the stock suspension too soft for non-RFT tires?

Thanks everyone for your opinions!

I've got A/S 3sport+ on my 640 and it's awesome. I changed from 20's to 19's for better ride also.