All 4 tires same size??

[jcb100]

Anybody know if you can run the same size tires on rear as on front? I drive my 03' over 1,000 miles per week highway and want to maximize tire wear by being able to rotate all 4 tires. In order to do this I need to equip. the rear wheels with same size tires as front. Tire shop says it will work?

Merc. dealer says no way as it will screw up ABS etc. as car is "programmed" for the larger rear tires. The Crown Vic police crusiers have all 4 same size so maybe it would work. I have heard some guys putting winter sets on MM's and they donot mess it up??

Help from anybody greatly apprectiated.

[Petrograde]

Welcome!!!!

I know a few people here are running 4 same sized tires,... Hopefully one of them will chime in soon.

I'm pretty sure you can get your EEC re-programmed (or just get a chip) that can be programmed to accommodate your wishes,.. not to mention add a few HP!

Winter tires: yes they were smaller rims but, they were taller tires. so the dimension stays the same.

Tom

[CRUZTAKER]

Yes it is possible, and no it doesn't screw up the abs. I ran same size tires all winter. Lot's of us do.

Dig a little deeper in the 'search' function and I'm sure you will find additional input.

Here is one to get you started: SAME SIZE TIRE THREAD (http://www.mercurymarauder.net/forums/showthread.php?t=7086&highlight=size+tires)

HERE'S ANOTHER (http://www.mercurymarauder.net/forums/showthread.php?t=7551&highlight=SIZE+TIRES)

AND YET ANOTHER (http://www.mercurymarauder.net/forums/showthread.php?t=4980&highlight=SIZE+TIRES)

[Dennis Reinhart]

You can change tire size in the EEC, but what happens is the ABS module is setup for the two different size tires, the front tires spin 4 MPH faster than the rear, if you install the same tires all the way around you will get traction control light if you have TC, I am working on a fix for this issue but it will not be cheap

[jgc61sr2002]

JCB100 - Welcome to the MM site. It is the best by far. Nice folks and good information. One thousand miles a week is a lot of driving. :beer: When DR speaks everyone listens. :D

[SergntMac]

Yes, you can run 4 tires the same size withour disruption to the ABS. I had 255/50 on all four corners without a problem for thousands of miles. Moreover, you can play with different sizes and combinations, as long as you stay inside a pre-defined ratio. I don't have the EXACT specs, but I respected a 1.05 tolerance between front and rear without problems.

Example...My 255/45 front tires are 27.04 tall. My 285/45 rears are 28.01 tall, and within the 1.05 limit. Should I change my rear tires to a 305/45, they would be 28.81 tall, and may throw an ABS code, that would go out when I took the tires off. I'm sure this can be corrected or shut off in the ECM. Traction control is another story I know nothing about. Here's a neat applet, 3rd down, to check your sizes.

http://www.speedworldmotorplex.com/calc.htm

[schuvwj]

I've ran the same size tires (as rear) for all four tires for over 4,000 miles.

No Problems at all!

[Murader03]

Yep! As long as you don't have TC. Well, you can do it then also, but the TC light will come on. I run the smaller front tires on all four corners. Speedometer is about 3.5 -4% high, but Dennis has curred this, or will have curred this when I get my tuner back. Otherwise, on my non TC equipped car, all's well. The car has 50K on it, and I've run the last 20K with the same size tires.

[RoyLPita]

Welcome aboard. I plan on running even sized tires when I get my MM. I also checked with Jason at Alternative Performance and he said he could recalibrate the speedo for even sized tires with a chip. I plan on doing this when it happens.

[Ross]

After I wore out my first set of tires, I went to the same size all around. Been that way for about 3,000 miles now and it's great.

[Thomas C Potter]

I had same size front and rear for winter, about 27.0", the TCS light will come on at about 36-38 mph and it feels like someone cut out 4 cylinders. But, simply turn off TCS switch, and all is fine. ABS is fine. I did not recalibrate anything.

TP Blue 03 B

[jcb100]

After I wore out my first set of tires, I went to the same size all around. Been that way for about 3,000 miles now and it's great.

What size did you use on all 4?

[CRUZTAKER]

JCB100, how about a little information from you. I would have asked before, but I figured by now you would have offered. What model marauder do you have? And do you have T/C? Did you READ the links I offered? Those folks tell you what size they are using.

[Stephen Soulsby]

I'm about to install four front 235/50/18's on mu car and get it alligned. I know it's only about 3% speedo difference, but is there a way I can get Ford or somebody to reprogram my ECM (code BMD0) so my speedometer reads correctly for free? I don't want Ford to give me a whole lot of :bs: if I ask them to do it.

I have a 300A

[RF Overlord]

is there a way I can get Ford or somebody to reprogram my ECM (code BMD0) so my speedometer reads correctly for free? I don't want Ford to give me a whole lot of :bs: if I ask them to do it.

Stephen:

The short answer would be NO...Ford will tell you the car is designed to have different size tires F & R, and any changes you make will be at your own risk...

I also doubt a dealer has the ability to go in and change only certain parameters in the programming the way Dennis/Wes/Lidio can. Their re-flashes are all-or-nothing batch transfers...

...and I've certainly never heard of a dealer doing ANYTHING for free...

[Stephen Soulsby]

Stephen:

The short answer would be NO...Ford will tell you the car is designed to have different size tires F & R, and any changes you make will be at your own risk...

I also doubt a dealer has the ability to go in and change only certain parameters in the programming the way Dennis/Wes/Lidio can. Their re-flashes are all-or-nothing batch transfers...

...and I've certainly never heard of a dealer doing ANYTHING for free...


So my question becomes, what are my options? I'm working with very little money right now since my hours have been cut at work.

[Ross]

Stephen, the budget can always be the killer for different options. After doing some research and talking with Mac about his tires, I went with Pirelli P Zero Assymetrico 255/50 all around and I love them. However, they cost roughly $1,200.00. Good thing this is a company car and my firm ate the cost, or I would have been on another set of OEM tires. The OEM's are still pretty cheap, and IMHO a set of the larger rear size all around should work well.

[Stephen Soulsby]

True they would work, but I saw some pics and I think it just looks goofy. Not to mention I think I can control the center tread wear better with the more narrow tires.

[woaface]

Tire rotation! I KNEW I forgot to do something last weekend...gah! I'm such a retartard...women are so distractive...

[jfclancy]

Dig a little deeper in the 'search' function and I'm sure you will find additional input.

Here is one to get you started: SAME SIZE TIRE THREAD (http://www.mercurymarauder.net/forums/showthread.php?t=7086&highlight=size+tires)

HERE'S ANOTHER (http://www.mercurymarauder.net/forums/showthread.php?t=7551&highlight=SIZE+TIRES)

AND YET ANOTHER (http://www.mercurymarauder.net/forums/showthread.php?t=4980&highlight=SIZE+TIRES)[/QUOTE]

Been running same size (rear stock) on all fours for about 4K miles no Problems whatsoever, I have had my 300A, with just over 20K miles, that I have had for slightly over a year. Without traction control the only things I noticed have been, IMHO ,slightly better handling to include better percieved braking. I have so far not had the wear pattern on the rears (center first) that happened on my first set since I went with 34psi.

Joe Clancy

[RF Overlord]

Stephen:

Unfortunately, I think you have only 2 options at this time...make all four tires the rear size, so the speedo won't need correcting, or live with the error.

Personally, I plan to live with the error when I put on 4 new front-sized tires this spring...I think having all 4 the rear size looks goofy, too...

With a 3% error, when the speedo sez 70 mph, I'll actually be going 68...big fat hairy deal...better than the other way 'round...