Another Tire Date Code Question

[Old Harry]

Checked the tire date codes on my 2012 Tiffin today. Whoever mounted the tires should be taken out back and whipped or they were told to hide the date codes, I wish I knew which.

The date codes on the steer tires were on the inside side of the wheels. The driving tires had the date codes mounted so that the codes were between the two tires. I had to use a small mirror on a handle to read those codes while on my back under the coach. It’s a good thing I’m dyslexic and can read numbers that are both backwards and upside down.

Anyway, what I find perplexing is the coach is a 2012 but two tires have a date of 4014 and the other four dates are 3914. How could six tires have codes from 2014 on a 2012 coach?

I have a hard time believing the original six tires had to be changed in only two years. Anyone have any ideas how this could be?


There is no crazing or cracking of the sidewalls. I have had the coach one year next month and it stays inside my barn safe from direct sunlight. I regularly treat the tires with UV protection so I plan on keeping them one more year before replacing them.

[MrMark52]

Since 2000, the coding is week and year - WWYY.

[R.Wold]

Originally Posted by Old Harry

Checked the tire date codes on my 2012 Tiffin today. Whoever mounted the tires should be taken out back and whipped or they were told to hide the date codes, I wish I knew which.

The date codes on the steer tires were on the inside side of the wheels. The driving tires had the date codes mounted so that the codes were between the two tires. I had to use a small mirror on a handle to read those codes while on my back under the coach. It’s a good thing I’m dyslexic and can read numbers that are both backwards and upside down.

Anyway, what I find perplexing is the coach is a 2012 but two tires have a date of 4014 and the other four dates are 3914. How could six tires have codes from 2014 on a 2012 coach?

I have a hard time believing the original six tires had to be changed in only two years. Anyone have any ideas how this could be?


There is no crazing or cracking of the sidewalls. I have had the coach one year next month and it stays inside my barn safe from direct sunlight. I regularly treat the tires with UV protection so I plan on keeping them one more year before replacing them.

The original tires were probably 2011 or even 2010 (my 2010 Bay Star had 2008 tires) and they were probably crappy goodyears and the previous owner had problems with them. So it’s easy to envision 2014 tires on it.

They could also have been in the group of 2010 Michelins that were recalled. My 2010 Phoenix had 2010 Michelins that we’re replaced under a recall in 2014. Brochure for 2012 30GA shows shows the tires as GXRV so they were Michelins.

Whatever the reason 2014 tires are ready to be replaced. I’m replacing my 2015 Michelins no later than early next year.

[TonyMac]

And now you know, it matters how a tire is mounted. I always insist the tire be mounted with the pressure next to the valve stem and the date out, unless there's a real good reason not to. I learned this from Heuly Picket, a mechanic I was apprenticed to in high school. Don't waste time doing it halfway.

[astrnmrtom]

Before heading out to full time a year ago in July, I had 6 new tires installed. ALL tires were installed with the date code on the inside. Not sure if it was intentional, but I can't imagine it was random. There was some variation in the dates, but not enough to be an issue. I wondered if it was because RV customers can be a pain when it comes to tire dates so they made it a little harder to check. Didn't stop me from grabbing my creeper and a flashlight. I'll never know why because I didn't ask. We hit the road and never looked back.

[Old Harry]

Thank you both R. Wold and TonyMac.

I was unaware of the Michelins recall but that makes a lot of sense. The tires on the coach are Bridgestones. When I have new tires put on I WILL insist the date codes and tire pressures be on the outside and where someone can read them.

[MrMark52]

Originally Posted by Old Harry

Thank you both R. Wold and TonyMac.

I was unaware of the Michelins recall but that makes a lot of sense. The tires on the coach are Bridgestones. When I have new tires put on I WILL insist the date codes and tire pressures be on the outside and where someone can read them.

FWIW - the tire pressure indicated on the tire is the “Maximum Inflation Pressure” and has nothing to do it the correct tire pressure you should be running he tires in the coach.

There are plenty of threads on this site that gives the proper procedure for determining the correct cold inflation air pressure that should be in your tires (I’ve done at least 4 or 5 of them).

[Old Harry]

MrMark52

Thank you for proper tire pressure information. I am aware of both what the date code WWYY and tire PSI to weight ratio should be.

I took TonyMac reply to mean car tires which are generally run at near max PSI. Our Toyota Prius calls for 45 PSI and I run the tires at 42. I was sure he did not mean RV tires which as you correctly pointed out is the MAX PSI for the tire and not the "running load" PSI.

For my coach weight 85 PSI is what Bridgestone calls for but thank you again for the reminder since we do have many "newbies" who may not know.

[Dutch Star Don]

Typically, the date code is on the back side of the tire, if you really want to get down to the nitty gritty of what is the front and what is the back. There are many tires that are only mounted one way. Some are rotation specific, some have different tread designs and some, like whitewalls, are obvious.

[THenne1713]

If code is put to face outside for front tire mount, they will be face/face hidden when mounted on REAR..

[R.Wold]

Originally Posted by THenne1713

If code is put to face outside for front tire mount, they will be face/face hidden when mounted on REAR..

heh - there is that .....

[TonyMac]

Originally Posted by THenne1713

If code is put to face outside for front tire mount, they will be face/face hidden when mounted on REAR..

Why? These are not directional tires. If you mount the date code on the outside on the front tires, the tires are rotating in opposite directions, left one clockwise and the right one counterclockwise, when looking at the date side. And that's ok, direction doesn't matter. So mount the tires any way you like. No need for hidden dates.

And the pressure on the sidewall is not the maximum pressure. It is the minimum pressure to carry the maximum weight. At least, that's what some Tireman told me. Where you at, Tireman? Did I get that right?

[R.Wold]

Originally Posted by TonyMac

Why? These are not directional tires. If you mount the date code on the outside on the front tires, the tires are rotating in opposite directions, left one clockwise and the right one counterclockwise, when looking at the date side. And that's ok, direction doesn't matter. So mount the tires any way you like. No need for hidden dates.
I think the key point here is that you have to be there hovering over the guy on the tire machine if you care how they are mounted. And most shops don’t like/allow that.
And the pressure on the sidewall is not the maximum pressure. It is the minimum pressure to carry the maximum weight. At least, that's what some Tireman told me. Where you at, Tireman? Did I get that right?

I think it’s the max load and the required pressure for that load - sounds like the same thing you’re saying.....

[Caliber]

The tire tech / dealer is not hiding the date code on purpose. Tires have balance Dots on the sidewall, the tech mounted that side of the tire on the valve stem side of the rim.

https://www.tirebusiness.com/article...erve-a-purpose