Anyone make the switch from 245/55r18 to 245/60r18? Big difference?

[crownvic]

Buying new tires for my 2014 PIU. Other posts have guided me to a logical tire choice, but should I buy the 245/55r18 (cop size) or 245/60r18 (explorer base size) tire sizes?

Tire calc says the width is the same, but the sidewall height is 9.1% taller on the 245/60s. I'm pretty sure I can set adjust the tire size to 245/60 with Forscan, so the real difference will be the ride performance.

I do like the way my PIU cuts , accelerates and stops with the 245/55s, but man do I miss the smoothness of my ole crown vic ride. Thoughts?

 

[peterk9]

The generally accepted rule is that when changing sizes you should not exceed the maximum diameter variance of OEM by more than 3%. The size you mentioned going to will exceed that slightly at 3.4%. The main reasons are that larger tires/wheels are heavier and will put more strain in brake and suspension parts as well as affecting programmed features such as ABS and Traction Control. in you case, I'm guessing the 0.4 difference shouldn't be problematic.
https://www.tacomaworld.com/tirecalc?tires=245-55r18-245-60r18
FYI, I use 18" tires in place of the OEM 20" for Winter and notice a somewhat better ride due to the increased sidewall height.

Peter

 

[peterk9]

The generally accepted rule is that when changing sizes you should not exceed the maximum diameter variance of OEM by more than 3%. The size you mentioned going to will exceed that slightly at 3.4%. The main reasons are that larger tires/wheels are heavier and will put more strain in brake and suspension parts as well as affecting programmed features such as ABS and Traction Control. in you case, I'm guessing the 0.4 difference shouldn't be problematic.
https://www.tacomaworld.com/tirecalc?tires=245-55r18-245-60r18
FYI, I use 18" tires in place of the OEM 20" for Winter and notice a somewhat better ride.

Peter

 

[crownvic]

The generally accepted rule is that when changing sizes you should not exceed the maximum diameter variance of OEM by more than 3%.

245/60r18 is an OEM size. It's the tire size that the XLT explorer model comes with. You can even use FORSCAN to adjust the internal modules to accept any stock/OEM Ford explorer size. I assume this recalibrates the speedometer, ABS, and traction control (PTU).

Other OEM/ stock wheel sizes for explorers are: 245/65R17, 255/50R20. I believe that any of those choices are selectable in the BCM (body control module) under address:
726-12-01 xxxx 0840 xx

https://forscan.org/forum/viewtopic.php?t=2650

I'm just asking you all if the ride improvement warrants me installing 245/60r18

 

[peterk9]

If your PIU came with 245/55R18, then that would be considered the OEM size and what all the features would be programmed for. A 255/55R20 would be OEM size for the Limited, Sport and Platinum. 245/60R18 is OEM on the XLT and retail Base Explorers. OEM size is what originally came on the vehicle from the factory. BTW, a 17" won't fit on a 2014 Explorer. Increasing the sidewall height will give it more flexibility and improved the ride on mine as stated. Whether the difference in ride is worth changing tire sizes for is hard to say. It usually comes down to a personal preference. Perhaps some others can give you a more definitive answer.

Peter

 

[Livernois]

I believe the only real reason they use the smaller sidewall for the police unit is to handle corners better. The stiffer sidewall won't flex as much and will more then likely come in a higher speed rating. It is not a huge difference but less sidewall means not as good as a ride but will handle better.

 

[KayGee]

I switched from 245/55R18 RSAs to a much lower profile 275/40R21 Pirelli Scorpion Verde NCS Noise Control All-Seasons and the ride was way nicer and quieter with the lower profile tires. Circumference of the 275/40R21 is within a few mm's of the 245/60R18. There's a lot more to ride quality/smoothness than just tire profile.

I am sure you can find a 245/55R18 that offers a decent ride. Best bet is to check out some of the tire reviews and befriend a local tire shop and find out about the 'test drive' policies of the various tire manufacturers and what the procedure is if you want to get out of one tire and into another within their test drive timeframe (usually 30-45 days).

 

[Livernois]

Not exactly apples to apples. Yes the sidewall height is slightly smaller on your tire swap but it is also over an inch in total height and an inch wider. So yes technically lower profile but not quite the comparison 245/55/18 to 245/60/18. but yes your 275/40/21 is same height pretty much as the 245/60/18 so I would expect that result

 

[KayGee]

Not exactly apples to apples. Yes the sidewall height is slightly smaller on your tire swap but it is also over an inch in total height and an inch wider. So yes technically lower profile but not quite the comparison 245/55/18 to 245/60/18. but yes your 275/40/21 is same height pretty much as the 245/60/18 so I would expect that result

The point of my post was that one doesn't need to go to a higher profile tire to get a better/smoother ride. There are plenty of low profile (55 series or less) tires that offer a nice ride quality. RSAs are not known for their stellar ride quality.

 

[CDW6212R]

Have you thought about the size right between those OP two choices? The OEM size is 28.5" tall, and the other is 29.5" tall. See what is available in a 255/55/18, which is a 29.0" tire.

I had 265/60/18's once, they were too heavy as a wheel/tire combination, so I changed to 255/60/18 on the next set, and lastly the 255/55/18's I have now. The ride quality is mainly determined by the tire brand, tire design, there's a big variance between tire models. Try to consider tire weight when you shop around, most good listings will include the tire weight. Tires with 10 plys of the same tire model will weigh a bunch more than a 5 ply version. That's common in many truck tires, to have two or three different load models of the same tire. For only street use, you should stick with the lighter tires for performance and fuel mileage.

 

[Eric Z]

Running with Goodyear Eagle Defenders 245/55R18 on a 2015 PIU and I like them. Better ride and way quieter than the same size Eagle Ultras plus the same speed and load ratings

 

[KayGee]

Have you thought about the size right between those OP two choices? The OEM size is 28.5" tall, and the other is 29.5" tall. See what is available in a 255/55/18, which is a 29.0" tire.

I had 265/60/18's once, they were too heavy as a wheel/tire combination, so I changed to 255/60/18 on the next set, and lastly the 255/55/18's I have now. The ride quality is mainly determined by the tire brand, tire design, there's a big variance between tire models. Try to consider tire weight when you shop around, most good listings will include the tire weight. Tires with 10 plys of the same tire model will weigh a bunch more than a 5 ply version. That's common in many truck tires, to have two or three different load models of the same tire. For only street use, you should stick with the lighter tires for performance and fuel mileage.

The explorer requires standard load range tires which are equivalent to 4 ply. The 6+ plys you speak of are more commonly found on LT tires. The XL load range are typically a higher rated 4 ply with reinfroced sidewall.

There is no reason anyone should need XL load range or 6 ply+ LT tires on an explorer 5g, but if they do put them on, they can expect ride quality to be worse than with a standard tire (103 load range for piu).