Down sizing tire size, upgrading load range, any thoughts?

Hello,
We are new to this great forum. We recently bought a 2004 2619 that came with ST215/75R14 Marathon radials. After reading about all the tire issues especially regarding 14" Marathon blowouts I decided to replace the OEM tires with either Kuhmo 857s, Maxxis, or Cooper load range D tires, plus the tires are 5 years old now. The present wheel-well clearance on top feels like it's less than 2". The increased load range per tire with 195/QR14 Ds or equivalent would be a min. of 200 lbs, and they should be a little narrower and not dent the sidewalls from the spare tire holder.
Is there a problem with running smaller height tires? I can't see why not unless I didn't replace the spare also, even then would it hurt to run two different size tires until the flat tire was repaired?

While checking the date code on the spare I checked the valve stem. I barely pushed it and it ripped open. Thanks to this forum I would never have thought about checking it. One of the other two stems is also rotten but not to such an extreme. We will have metal stems installed with the new tires.

Lastly, I think we are going to order the Doran 360RV TMS. I spoke to a Doran rep and he said they expect the sensor batteries to last from 5-7 years. Replacement sensors now cost 29.95. I'm trying to decide if we should spend an extra $30 for a sensor for the spare or not be lazy and do some crawling before each trip. Gary

[ShrimpBurrito]

I can't see any reason why running smaller tires would be an issue. I think the weight rating is key here. Theoretically, your fuel economy will increase because the tire/road contact surface is smaller, but it's probably too insignificant to notice. The same is probably true for the decreased braking effectiveness. But that's just my guess.

I'm not a gambling man, but I would place money on a bet that you would not check the air in the spare before each trip. Mine is mounted on the rear bumper, isn't covered, and I don't check it.

Dave

After our last blowout I pulled out the spare and it only had about 35 lbs of pressure in it, and that after replacing the valve stem on it after a blowout only a couple of months previously. Luckily we didn't have far to go to get home, but now my wife makes me check the pressure on the spare also before we leave home. And ours is mounted underneath, so it isn't easy

Changing the tires may be a good idea, and the valve stems with the new sensors is probably a must do. The original tires have lasted 4 years without an issue so they worked for the previous owner. We traveled over 3,500 miles our first year and 2,000 miles our 2nd before we had a flat. We stayed off the interstate the 1st year and drove under 60 mph. The 2nd year my wife got sick at the end of vacation and so we jumped on the highway to get home faster and increased the speed to 65-67. That is when we had trouble, one blowout on the driver side one day and we stopped and got a new spare. The next day a flat on the other side after a few hours of driving. Stop and get another new tire. I put the old spare back into storage and had two new tires for the rest of the trip. Barb started feeling better and we slowed down and got off the interstate again so we could enjoy the scenery. I wish I had known about this site before, I really think the speed is a killer on the original tires. I will be changing the stems and have a monitor system before we go on another trip for all three tires.