Best national tire chain to buy 6 new tires?

Just a smidge under 10". I did the best I could but the two tires don't line up exactly and there are 5 sections of swerving treads and I had to pick a spot and do my best.

Yes M'am. That is correct. Six Inch Wheels. From what CapriRacer said, starting to look more and more like those 8.75's are gonna work.

We can confirm it, with your Dually Spacing Measurement.

Cheryl_B wrote:
Okay. Here's what the tag on the doorjam says.

They are the dreaded 16.5's.
March 1985 seems to be the date for the Chassis and anything else on that tag.
Although near GVW (10,500), it does say "4/85" which would be April rather than March.
"Front- 3,900 with 800 x 16.5 D
Tire 16.5 x6, rims 60 PSI"
"Rear-7,200 with 800 x 16.5 D, 60 PSI cold dually."

This is everything on the tag. So they are 6" rims?

CapriRacer wrote:
And if I am right that Cheryl has 6" rims, the spacing could be as low as 9 1/2" and still be good - and based on my experience, there is some additional clearance to make sure things work out, so I'm guessing if the spacing is 9 1/4" or greater, Cheryl should be good to go!

So Cheryl, measure carefully. Find the same spot on each of the tires, and hopefully the tires are the same brand and type.

Take another look at that label where you found 16.5 and see if the Rim Width is there. I just looked at ours (2002 Ford with 16" wheels) and the label says "16x6" which is Diameter x Width, and we're looking for 6"...

I appreciate all the help. Sorry for my little outburst. Just can't believe how different reality is from the dream, ya know? Reality bites, as they say.

And if I am right that Cheryl has 6" rims, the spacing could be as low as 9 1/2" and still be good - and based on my experience, there is some additional clearance to make sure things work out, so I'm guessing if the spacing is 9 1/4" or greater, Cheryl should be good to go!

There are no Discount Tire Stores in Alaska.

Wow. Thank you for trying so hard to find the answers by looking at another Chevy Class C. It's hot and nasty here so I will get those measurements up here for all to see by tomorrow. Heading into a less humid, cooler period. I'm hiding inside and pretending I have no cares in the world. I'm very good at avoidance.

CapriRacer wrote:

The minimum dual spacing for an 8.00R16.5 is 9.0" and for an 8.75R16.5, 9.9". That means that the gap between freestanding duals is 1" and 1.15" respectively.

Now I'm going to guess that Cheryl has 6" wide rims, and that means we get 0.3" more to play with.

I'm trying my best. I had errands this morning, so I took my "offset gauges" (a piece of 2x4 and a couple thinner boards, thinking I'd stop at a Chevy based Class C I'd seen sitting for sale in a strip mall parking lot. Reach under and check. Coach was gone.
Then I went to a tire store and asked for the Offset Specs on 8.00 and 8.75 tires. All they could offer was to bring in a couple 8.75's, dismount a pair of 8.00's, mount 8.75's and see what the spacing was. They knew about offset/sidewall clearance, but could not find the specs in their sources, including a call to the tire distributor.
Tires in question were Firestone Transforce, so I pulled up firestonetires.com, and requested "Chat with an Agent" but no reply. I doubt I'll get through before the holiday (maybe the holiday week) is over.

Time to figure out Cheryl's actual Rim Spacing, so:

CHERYL: Front and Center!

In this diagram, posted above, copied here to make it easier for you,
The two top surfaces represent the tread surfaces of a pair of dual tires.



The two words at the bottom are "Dual Spacing" and they're showing it being measured from a point in each rim, that you can't see unless the tires are off the rims.

BUT! You can take your trusty 12" ruler, and measure from any point on the tread of one tire to the same point on the tread of the other. Say a groove runs right down the center of the tread of your tires. Measure the distance from that groove of the inner tire to the same groove on the outer tire.

THAT is your Dual Spacing Specification!!! With that, we can look at Barry's spec of 9.9" and see if you're safe. 9-7/8" is about 9.9" so you're good. More doesn't hurt. I'd go 9-3/4" but much less is a concern. That's just me, and I've been around a lot but I'm NOT a Tire Man and CapriRacer is.

Shouldn't be this difficult, but remember, the kid at the tire store, even the assistant manager, was in K4 when Chevy quit 16.5" tires.

Cheryl_B wrote:
I'm sorry, but y'all are overwhelming me. I don't know what I got myself into with this thread. I'm over my head. I just want new tires. How hard can this possibly be? The tire people do know how to do their job, right?

And I GAVE you the answer that you NEED......twice.

The "national tire chains" operate on volume. They do cars and light trucks. Most of them REALLY don't want to mess with motorhomes and big trucks AT ALL. As a result, they know little about them.

FIND A TRUCK TIRE SHOP NEAR YOU. Call ahead to tell them what you have, get prices and make an appointment. DONE.