Running mixed tires?

[ctrlraven]

I'll be getting some KDW2's this week for the rear (255/55-18) and I will still have on the 235/50-18 kdws stockers on the front. Now I know its a big no no to mix same axle tires but would my tire setup be ok as a daily driver for the next month or so until I can get some kdw2's for the front?

[mcb26]

Been running that setup for 18k miles. No major problem. Makes the car push a little and grooves in the pavement make lane changes intresting.

[ctrlraven]

Yeah I figured it wouldn't like grooves in the pavement like normal, thanks for the reply, now it's time to order them. :burnout:

[RoyLPita]

I have this setup, too. My fronts are due for replacement, though.

[sailsmen]

I ran the same set up until the fronts wore out w/ no probs. Just remember you have 2 diff sets when you drive it.

I ran Nitto DR for 15K, and I could never forget they were back there.

[magindat]

Been runnin Nitto 420 in 20" rear and Nitto 555 in 18 in front for over 30K. I think it handles better and more predictable and auto-x times are comparable to other marauders.

[High-C]

Has anyone figured out a combination for these tires on our cars? Especially with TC?.... Rich, anyone?

http://www.bfgoodrichtires.com/specs/g-force-t-a-kdw/22.html

[ctrlraven]

The combo I will be running will be 245/45ZR18 on the front and 255/55VR18 on the rear. 2.2" difference in height won't give the traction control any problem. I don't plan on taking the car past 149 mph so the speed rating difference means nothing to me lol.

Someone said the abs module has to see a 1.2 % or " difference between the front and rear tires for everything to work properly.

[High-C]

The combo I will be running will be 245/45ZR18 on the front and 255/55VR18 on the rear. 2.2" difference in height won't give the traction control any problem. I don't plan on taking the car past 149 mph so the speed rating difference means nothing to me lol.

Someone said the abs module has to see a 1.2 % or " difference between the front and rear tires for everything to work properly.

Just for clarification... You have KDW tires in the rear (255/55VR18)

and stock KDWS (245/45ZR18) in the front?

[Breadfan]

No, OEM front is 235/50/18.

That size is also available in the KDW2.

[magindat]

Has anyone figured out a combination for these tires on our cars? Especially with TC?.... Rich, anyone?

http://www.bfgoodrichtires.com/specs/g-force-t-a-kdw/22.html

I don't have TC (and I like it), so I can't answer to that. Sorry.

Look at revs/mile, though. Tire wear alone can account for 20ish revs/mile, so there has to be some 'slush' to account just for tire wear. I would then assume that staying within about 20-25 revs/mile on a different tire should be OK? Just an educated guess, though.

I do know that manufacturers vary in their revs/mile rating on the same size and aspect ratio tire. This could account for the vast confusion about why a different size tire from mfg A works, but mfg B doesn't.

My only experience (as a ricer) is Honda ABS wants no more than 7% difference or ABS doesn't work right due to wrong number of counts per MPH.

[Breadfan]

Has anyone figured out a combination for these tires on our cars? Especially with TC?.... Rich, anyone?

http://www.bfgoodrichtires.com/specs/g-force-t-a-kdw/22.html

Also if you haven't seen this yet this should list a number of good combos, there are atleast 2 with the tires you link above.

This is up for some revisions and additions this year...but still good info

http://www.mercurymarauder.net/reviews/showproduct.php/product/47/sort/2/cat/18/page/1

[ctrlraven]

Just for clarification... You have KDW tires in the rear (255/55VR18)

and stock KDWS (245/45ZR18) in the front?
The new rears will be KDW2. My current front will be 235/50-18 KDWS (oem) tire for the mean time until I can order some 245/45-18 KDW2 to replace them.

[mcb26]

Mine are 255/55 2's rear and 235/50 "s front no problem with TC.

[High-C]

The new rears will be KDW2. My current front will be 235/50-18 KDWS (oem) tire for the mean time until I can order some 245/45-18 KDW2 to replace them.

That sounds like what I'm looking for... not right away, but maybe this summer. I love the looks of the KDW tires vs the KDWS... Let me know how they ride etc and shoot us some pics of those bad boys from the rear... - C

[High-C]

I don't have TC (and I like it), so I can't answer to that. Sorry.

I'm sure that it's been discussed here before but... If there is anyone here that could help me figure this out, it's you. I want to reverse the TC Off button so that the TC is only on when I hit the button, on demand. I want the light on only when it is engaged, not when disengaged like it is now. Any easy fixes?

[ctrlraven]

Oh I will, one of my buddys takes great pics and he will be with me this weekend when I hit the track. I agree the tread pattern on the KDW2 series tire is just sexy.

Plus I have a winter wheel/tire setup so the warm weather tires will last just that much longer since I do about 18-20K miles per year.

[ctrlraven]

I'm sure that it's been discussed here before but... If there is anyone here that could help me figure this out, it's you. I want to reverse the TC Off button so that the TC is only on when I hit the button, on demand. I want the light on only when it is engaged, not when disengaged like it is now. Any easy fixes?

Yeah, start the car and then turn it off. When you want TC push the button again lol. :P

My current summer tires are 235/50-18 all around so I had to get used to turning the TC off before I started driving cause other wise 60% or more throttle and anything over 45mph it would kick on.

[magindat]

I'm sure that it's been discussed here before but... If there is anyone here that could help me figure this out, it's you. I want to reverse the TC Off button so that the TC is only on when I hit the button, on demand. I want the light on only when it is engaged, not when disengaged like it is now. Any easy fixes?

Drock96marquis seems to have a terrific handle on the stock electronics. Perhaps he'll chime in.

That question might be worthy of a new thread.

[High-C]

Drock96marquis seems to have a terrific handle on the stock electronics. Perhaps he'll chime in.

That question might be worthy of a new thread.
Consider it done... New thread started... Thanks Rich...

[BigCars4Ever]

Been running that setup for 18k miles. No major problem. Makes the car push a little and grooves in the pavement make lane changes intresting.
That's cause you changed your alignment by raising the back of the car. Lower the back about 3/4 of an inch and it will go back to normal or have the car re-aligned. I opted to lower mine.

[teamrope]

I've run the KDW2s for over a year now, and the only things I like are the tread wear and the traction is a little better. However, they pull harder in ruts than the KDWS, they make more noise, and to be honest, their performance in any kind of snow or ice is unacceptable. (Downright dangerous in fact.) Also the larger size on the rear throws my speedometer off by somewhere between 3-4 MPH at 55 MPH and even more at higher speeds.

I know that the KDW2s are rated one of if not the best wet/dry tire combo in sizes that are a close fit to our cars at the tire rack and that's fine in most cases. However the chart is assuming that you are running the exact same wheel on all 4 corners, and does not take into account that the front size KDW2 have a Z speed rating but the rears are only rated at V. I've never been totally comfortable about that.

[ckadiddle]

I am running KDW2s with 235/55 fronts and 255/55 rears. Traction Control likes the combo fine. These are designed for Dry or Wet conditions ONLY. The OEM style are named KDWS for Dry, Wet, Snow.

They are good for my purposes in FL, 90 percent city driving in Orlando. They seem to be wearing better than the OEMs did, I am running 35 psi. They do a pretty good job of protecting the whels from curb, I really had to work at it hard in a Taco Bell drive-thru to screw up my rim.

[ctrlraven]

What psi is everyone running at with the KDW2s on the rear? I was thinking 35-36psi?

[mcb26]

What psi is everyone running at with the KDW2s on the rear? I was thinking 35-36psi?

35 psi front and rear

[ctrlraven]

That's what I thought.

[ckadiddle]

35 psi front and rear
Same here. A tad hard and bouncy sometimes, but I will trade a little bit of softer ride for a longer stretch between tire purchases.

[magindat]

I really had to work at it hard in a Taco Bell drive-thru to screw up my rim.

Hope that burrito was worth it!!! ;)

[ctrlraven]

I can't stop touching these tires, I'm in love with the tread pattern lol.

[ckadiddle]

Hope that burrito was worth it!!! ;)
I didn't need Taco Bell, it was the womenfolk in the car with me that needed a TB fix.

[ctrlraven]

For the guys that are running 255/55-18 KDW2 tires what Revs Per Mile did you change your speedo to? I have an xcal 2 unit but like with my snow tire size I've gotten several different RPM listing to set it to.

[mcb26]

Got my tune from DR with the correction. Not sure what he used.

[Black Terror]

Use the Miata Calculator, it is closest to Mathematical solution.(5280 x 12)/Circumference(91.23in)=694.51
I used 695 revs per mile for my car with XCal2 programmer.

[High-C]

Got my tune from DR with the correction. Not sure what he used.

So basically, We can correct our tunes to whatever tire diameter / revs per mile of whatever tire that we choose? This may be a silly question, but I wanted to be sure that if changes are made that they work properly....

I was thinking...

KDW 235/50 ZR18 front - 762 revs / 27.3 diameter

KDW 255/55 ZR18 rear - 717 revs / 29 diameter

But I could basically do whatever I feel as long as it's not waaaaay off?

[ctrlraven]

Yeah if you have a flash tuner device like and SCT Xcal2 or Diablo Predator. The only option is to correct the revs per mile for the rear tires so your speedometer will be actually showing what your really going.

Like I said before I've gotten several different RPMs to use from different sites. My current rear tire is my snow tire which is a 255/70-16 and it's RPM is set at 685. BFG says 717 revs per mile and the Miata tire calculator says 694. So it's like I'm playing the guessing game all over again, had the same problem with my snow tires and being told different RPMS.

Does everyone else have their's set at 695?

[Hotrauder]

I am running 4.10's and Nitto 295/45/18 rears and was concerned about actual speed. My Garmin GPS says my speedometer is 1 MPH slow @ 80 MPH. I do not know how to relate this to any other situation, so this is for info only. Dennis