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When are brand new tires considered "broken in"? Poor steering response on 15s compared to 17s.

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#1
Not sure if it's because my brand new tires still have mold release coating them or what, but so far I have about 50 miles on 195/55/15 BFG Sport Comp 2s, and compared to bald stock tires on 17s, the steering response is no longer quick and agile, it feels like im driving a boat. Am I driving on water balloons or do I need to give these tires some time to get sticky? I spent last night just weaving back and forth on abandoned roads trying to "break in" my tires.... feels horrible compared to stock. The response is so slow.


Any experiences or thoughts to share? Do i need to drive like 100 miles? Am i reaching a conclusion simply too early? Was going down to a 15 inch wheel a mistake?
 


Zormecteon

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#2
15" wheels with tires the same outer diameter .. that is /55 series tires will have a larger side wall, so of course be not as responsive, as the side wall flexes more.

If you got them to drag race rather than for cornering prowess, you've gone the correct way. .. tests show that for every inch you go up in wheel diameter after the first jump from stock .. ( stock base Fiesta has 15s (?).. you loose 5% in fuel economy and about 1/2 second in the quarter mile. .. IIRC. t..

If you got the
 


CanadianGuy

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#3
Side wall flex is your enemy here not necessarily the tire. Comparing 17 with 15 that is a challenge. Try increasing pressure but that will only go so far before it is not safe.
 


Pete

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#4
Most tires take 200 miles for the mold to be completely gone. I noticed this to be true with all the tires I have ran, star specs, rs3, re71rs, even the advan a048. Another thing to note is tire when worn down to almost no tread have better steering response then the exact same tire with maximum tread. All these will be a factor along with the sidewalk flex.
 


M-Sport fan

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#5
The mold release compound still being in the tread should have NOTHING to do with the setups actual steering response! [nono]

That is exclusively the realm of the; sidewall height/ratio, sidewall and carcass construction, and 'stretch' (to a point), so I would not expect that setup's response to get better after the mold release is all gone.
Ultimate grip YES, absolutely, but not steering response.

When I hear this type of complaint, it makes me want to say "eff the un-sprung weight penalty" and go with some 17x8s with 215/40s on them. ;)
 


OP
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The mold release compound still being in the tread should have NOTHING to do with the setups actual steering response! [nono]

That is exclusively the realm of the; sidewall height/ratio, sidewall construction, and 'stretch' (to a point), so i would not expect that setup's response to get better after the mold release is all gone.
Ultimate grip YES, absolutely, but not steering response.

When I hear this type of complaint, it makes me want to say "eff the un-sprung weight penalty" and go with some 17x8s with 215/40s on them. ;)
I agree. I'll see what happens here, as I know I was comparing bald tires to these new ones with lots of tread, as well as more sidewall, but so far I feel like I made a 1200 dollar mistake going to 15s as the steering response is absolute garbage.

I thought i did my homework, saw someone mention it but said it was minimal. Was expecting some change... but this is... an entirely different car now unfortunately.

Only possible remedies I can think of at the moment.

1) more air pressure, risk of weird wear pattern.
2) stiffer more summer oriented tires.
 


Pete

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#7
Just noticed you went with a 55 series. That is a big difference from the 40 series that come stock. Maybe you could possibly do a trade with a tire shop with your pretty much new tires with a 50 series summer tire. I ran 195/50/16 on track (yoko Advan A048) and the steering response was pretty good but not as good as a 205/45/16 I ran prior. Ultimate grip though was way up with the better compound of tire.
 


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#8
Tire is too thin and too tall. That's the issue I am seeing here IMO. It was a big reason I chose the 205/45/16 sizing for my RE71R vs the 205/50/16 sizing, despite being more expensive and slightly smaller diameter (0.2") than stock. I wanted that crisp turn in and feedback. I have no regrets on that front. Going up too far from that oem sidewall height of 40 will cause things to get doughier and doughier feeling. I notice it with my Pilot Super Sports (205/45/17) despite those being a normally very communicative tire to a lot of people, but I took them on the track anyways yesterday and liked them a LOT more than when I took the RE71R the first time before that. It's just the game we play with physics and it's why I think outside of drag racing, a 15" tire is a bit excessive as far as size dropping is concerned. I think 16" is the sweet spot. :)
 


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Tire is too thin and too tall. That's the issue I am seeing here IMO. It was a big reason I chose the 205/45/16 sizing for my RE71R vs the 205/50/16 sizing, despite being more expensive and slightly smaller diameter (0.2") than stock. I wanted that crisp turn in and feedback. I have no regrets on that front. Going up too far from that oem sidewall height of 40 will cause things to get doughier and doughier feeling. I notice it with my Pilot Super Sports (205/45/17) despite those being a normally very communicative tire to a lot of people, but I took them on the track anyways yesterday and liked them a LOT more than when I took the RE71R the first time before that. It's just the game we play with physics and it's why I think outside of drag racing, a 15" tire is a bit excessive as far as size dropping is concerned. I think 16" is the sweet spot. :)
Ya, this is unfortunately an expensive lesson that there are a number of variables to consider before deciding on a wheel and tire combo.

I was going for lower rotating mass, and to an extent, traction for a daily driver tire, that and I thought the 15's look cool.


What I didn't think about was just how soft the sidewalls can be and what that does to steering response. I have not had a chance to take the car out for a fun drive, but I can tell you that the driving dynamics have changed so much that it feels like an entirely different car.

I currently miss the quick-crisp response from flicking the steering wheel. I also feel like the weight transfer takes FOREVER with this wheel/tire combo.

Turn steering wheel for the round about.
slight delay
Front tires turn.
slight delay.
front end weight transfer settles
slight delay.
rear end weight transfer settles

It is the WEIRDEST feeling. Like driving on water balloons and likely due to the elasticity of the tire and how much sidewall there is. As an FYI , this 195/55/15 tire is actually the same diameter as the stock tire (23.4"). The tread depth is 9/32" (something that can also cause the water balloon response, compared to BALD tires), and a tread width of 7.7" and 7.9" section width measured on a 6 inch wheel (mine are 8) according to tire rack.



I honestly think the negatives do not outweight the positives with this wheel tire combo, but I will also wait until I get a chance to have some fun before I make a final conclusion.

I'm curious what some of these guys on 15's with stickier tires (and likely stiffer sidewalls I would hope!!!!) have to say about steering response.

They'll have to work for now, as I bought this tire because I have plans to do some rallycross for fun, and drive some gravel roads, but if I want better steering response with 15 inch wheels, I'm going to have to evaluate the summer tire options.

If I wasn't married, I would bite the bullet on this purchase and either buy new summer tires (stiffer sidewall hopefully) to see if I could get the steering response to a reasonable level or sell the combo and go back up to a 16 or 17 inch wheel, rotating mass be damned. But I'm stuck with this combo for a while.

 


M-Sport fan

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#10
^^^And yet, THAT tire is still being touted as the "be all, end all" for 15" street tires for this car by the 'gurus' on here? [???:)]
 


CanadianGuy

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#11
Ya its unfortunate but take it from a canuck that runs 15" 5-6 months a year for winter. 15 sidewall are weak, which is why they can absorb pot holes and bumps. Maybe a run flat would suite you more but I know even stiffer truck tyre side walls help to handle a larger/heavier load but at lateral speeds (turning) its about leverage and the fulcrum at the rim. Changing the camber may help as well but I'm pretty sure the Fiesta is limited there.
 


OP
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^^^And yet, THAT tire is still being touted as the "be all, end all" for 15" street tires for this car by the 'gurus' on here? [???:)]
Ya. I am.... disappointed.

It's probably a great tire for a majority of people. But as soon as I did a quick left to right test, I thought my lug nuts were not torqued down correctly because the response was sooooo damn slow. For putting miles on your car, probably a good wheel/tire combo, but if you enjoy precision steering, I am beyond disappointed at the moment. This is just in town driving, still need to head out for a fun drive and see what happens. Buyer beware!
 


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#13
I am running these tires in the same size and I LOVE it. How wide are the wheels you have them on and what pressures are you running? I have noticed only a hint of steering response loss, which I would trade all day for a little more comfort. I drive my car like I stole it and would never consider going back to 17s.
 


Capri to ST

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#14
I want to reduce my rotational and unsprung weight, which is one of the best things you can do for any car, but also want to retain the stock quickness and crispness of the steering response. My plan is to get Pro-Race 1.2's with OEM 17" specs and reuse the stock RE050A tires (my car's brand new). This will save me about 5 lb. per wheel, which is enough to be quite significant in my experience, without a huge financial cost.
 


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#15
Most tire places have a short return policy. If you're within that time frame, you could return them for something else.
 


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I am running these tires in the same size and I LOVE it. How wide are the wheels you have them on and what pressures are you running? I have noticed only a hint of steering response loss, which I would trade all day for a little more comfort. I drive my car like I stole it and would never consider going back to 17s.
15x8 TD 1.2 wheel. 39 and 36 is what is recommended for stock wheel and tires, im about 41 front and 38 back. I can roll the tire past the wear triangle when I'm trying to flick the car around testing out the initial bite.
 


M-Sport fan

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You could try going higher in small increments, but at some PSI point, you are defeating the whole 'ride comfort' supposed advantage of going to 15s touted by so many on here.
 


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#19
15x8 TD 1.2 wheel. 39 and 36 is what is recommended for stock wheel and tires, im about 41 front and 38 back. I can roll the tire past the wear triangle when I'm trying to flick the car around testing out the initial bite.
That is likely your issue. I am running 36 /34 hot. Bigger tires = less psi.
 


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That is likely your issue. I am running 36 /34 hot. Bigger tires = less psi.
Thanks for replying. From what I understand, less PSI, more sidewall flex. An example of this is a bicycle tire. I would assume if I was having issues with traction that less psi would work because i would have the sensation of sliding around with an overinflated tire... but i'm willing to try anything! At least that's my understanding.

What's the benefits with less PSI and bigger tire?
 


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