rear tire size changed to same as fronts?

[460mudsports]

Has anyone changed their rear tires to the same size as the fronts? I have done my best to research the threads and all I have found are people trying to stay as close as possible to the factory size of 245/55 18 or go larger. I know the smaller 235/50 18 fronts won't give quite as much contact patch (about 3/8" narrower). Making all 4 tires the same size would allow for rotation and the spare to work for extended driving, like during a flat at 3am 250 miles from anywhere. Putting the smaller diameter on the rears also has the same effect as keeping stock tires and re-gearing to 3.73. If you reprogam with a SCT SF3 or X3 for the smaller diameter tires, does this make the ABS and speedometer work correctly? My car is a daily driver and having a spare that would work for extended distances is much more important to me than the slightly increased dry traction of the larger tires.
Any help or suggestions would be appreciated.

[red]

The ABS should work correctly with this setup; I recall another member using the front size on all four corners. However, if you have traction control (e.g., a 2003 300B or 2004 MM), then this size change may cause it to engage. Reprogramming the ECU does not change ABS or traction control situation; it will allow you to correct the speedometer/odometer for changes in tire revs/mile or axle ratio.

[460mudsports]

Thanks Red.
I believe my car is an early 03. I know it was made sometime in 02, but I am not in it at the moment to look. I do not have a button for traction control.
Does anyone else have any knowledge or experience with doing this?

[red]

I believe my car is an early 03. I know it was made sometime in 02, but I am not in it at the moment to look. I do not have a button for traction control.
I don't know the cut-off date (there were a few muts in between), but it's likely a 300A considering date and the lack of a traction control button.

Does anyone else have any knowledge or experience with doing this?
Several 300A owners are running same-sized tires on all four corners; most are using rear-sized tires (or close to). As I mentioned, there was a member who recently posted about running front-sized on all corners (look through this forum--Tires & Wheels).

[SC Cheesehead]

I ran 245/45/18's (rears) on all four corners so that I could rotate them. Increased tire life by about 50%, but the darn things (BFG's) still wore out in the middle.

I've got a 300B, so I did experience T/C issues, but I just got used to punching off the T/C whenever I started the car up.

Have since gone back to the staggered configuration with OEM 235's in the front and General Grabber UHP 255/55/18's in the rear. So far, so good.

[gilby04]

I ran 245/45/18's (rears) on all four corners so that I could rotate them. Increased tire life by about 50%, but the darn things (BFG's) still wore out in the middle.

I've got a 300B, so I did experience T/C issues, but I just got used to punching off the T/C whenever I started the car up.

Have since gone back to the staggered configuration with OEM 235's in the front and General Grabber UHP 255/55/18's in the rear. So far, so good.

I tried the 245/55/18 setup on all four corners in 2006 for one month.
The ride quality of my DTR was definitely softer.
I then tried the 235/50/18 setup on all four corners for one month for comparison. The ride quality was noticably more harsh & bouncy.
The center wear issue of the 245/55/18 does not concern me to the same degree as does the loss of the raked appearance when using same size tires all around, so I have since returned to the OEM staggered configuration.
I've wondered if the 245/55/18 in front and the 255/55/18 in rear would be an improvement in ride quality while still maintaining the raked appearance ???

[red]

I've got a 300B, so I did experience T/C issues, but I just got used to punching off the T/C whenever I started the car up.
Did you ever have any problems with the ABS, e.g., at high speeds or on long trips?

[red]

I tried the 245/55/18 setup on all four corners in 2006 for one month.
The ride quality of my DTR was definitely softer.
I then tried the 235/50/18 setup on all four corners for one month for comparison.
Do you have traction control? If so, did you have any ABS issues at high speeds or after long trips with either size?

[gilby04]

Do you have traction control? If so, did you have any ABS issues at high speeds or after long trips with either size?

Yes, I have traction control. I had to disable traction control at speeds above 50 mph with either tire size, otherwise the engine would stumble.
No problems with ABS at any speed with either tire size.
The DTR has been my daily driver for over 5 years now, mainly for city driving.
However, there have been several occcasions travelling continuously at 70-75mph for an hour or two without experiencing any problems.
I typically don't drive faster than 75 mph, but I wouldn't expect any driveability problems at higher, or more spirited speeds.
A long trip in my book is 3 hours or more, so I take my Mountaineer that is much more comfortable.
Hopefully, my tire size experiments have been helpful for you.
As a general comment, the DTR is the fourth vehicle that I've owned that has had the traction control feature, and, in my opinion, is of minimal importance. The ABS feature is definitely more desirable.

[red]

Yes, I have traction control. I had to disable traction control at speeds above 50 mph with either tire size, otherwise the engine would stumble.
No problems with ABS at any speed with either tire size.
The DTR has been my daily driver for over 5 years now, mainly for city driving.
However, there have been several occcasions travelling continuously at 70-75mph for an hour or two without experiencing any problems.
I typically don't drive faster than 75 mph, but I wouldn't expect any driveability problems at higher, or more spirited speeds.
A long trip in my book is 3 hours or more, so I take my Mountaineer that is much more comfortable.
Hopefully, my tire size experiments have been helpful for you.
As a general comment, the DTR is the fourth vehicle that I've owned that has had the traction control feature, and, in my opinion, is of minimal importance. The ABS feature is definitely more desirable.
Thanks for the information! :coolman:

[460mudsports]

Thanks to everyone for the information. This has been quite helpful and I was finally able to to find the other threads on this as well. I am going to change to all four of the same size, I just haven't decided on a size yet! I have been looking at 235/55 18's as an inbetween compromise on sizes and may even consider 225/60 18's as a possibility depending on what tires I decide to try. This car is one of my daily drivers and my commute is 85 miles a day on flat straight roads, so I am more concerned with all around all-season traction, mileage, and tire wear than with track type traction and handling. Yes I did say mileage, but then I bought my Corvette as my other daily driver because it consistently gets 27 to 30 mpg.

[red]

I am going to change to all four of the same size, I just haven't decided on a size yet! I have been looking at 235/55 18's as an inbetween compromise on sizes and may even consider 225/60 18's as a possibility depending on what tires I decide to try. This car is one of my daily drivers and my commute is 85 miles a day on flat straight roads, so I am more concerned with all around all-season traction, mileage, and tire wear than with track type traction and handling.
235/55 and 225/60 18's are too tall and narrow and will have too much sidewall flex. Similarly, you should (at a minimum) match a speed rating of W to ensure sufficient sidewall stiffness. It's not a matter of performance, but rather safety, so I strongly suggest going with a tire appropriate for the Marauder's weight and suspension, which is "tuned" differently from other Panther platform cars. We've had a few members including a vendor wreck as a result of poor tire selection.

[BlackIce]

235/55 and 225/60 18's are too tall and narrow and will have too much sidewall flex. Similarly, you should (at a minimum) match a speed rating of W to ensure sufficient sidewall stiffness. It's not a matter of performance, but rather safety, so I strongly suggest going with a tire appropriate for the Marauder's weight and suspension, which is "tuned" differently from other Panther platform cars. We've had a few members including a vendor wreck as a result of poor tire selection.

Red,

Could you elaborate on that a little for me? I'm considering a 225/70/16 for rear winter tires but am concerned about performance issues i.e. unsafe driving characteristics. Would a 235/65/16 be sufficiently better suited to this application?

Thanks!

[red]

Could you elaborate on that a little for me? I'm considering a 225/70/16 for rear winter tires but am concerned about performance issues i.e. unsafe driving characteristics. Would a 235/65/16 be sufficiently better suited to this application?
In cold temperatures, different compounds and constructions are used to keep the tread pliable and planted to the surface. A narrower tire increases the pressure per area on the roadway and special tread designs increase channeling of mud and snow to ensure contact. A taller sidewall may further improve the contact area and maintain pliability since there is more deflection and accordingly more heat. As far as safety is concerned, your car will handle differently with taller sidewalls and will require you to re-learn its handling characteristics, though you should be driving more cautiously in the Winter anyway. I don't know whether a 225 or 235 is more appropriate, so you should probably consult owners from the North.

TireRack has some Winter tech articles you may find useful (click here (http://www.tirerack.com/winter/tech/index.jsp)).