Spare tire help

[sdsferraro]

I have a 2016 Wildwood 27RKSS, it has ST205/75r15 tires. Since the TT did not come with a spare and we have a long summer trip planned, I am planning on getting a bumper mounted spare. I see 3 different 5 lug bolt patterns. Can some direct to which is the correct pattern. I see 4.5, 4.75, and 5" bolt patterns.

Also the current tires,which only have about 150 miles on them, have C rated tires. I see better deals on mounted D rated than C rated. Would it hurt as a spare to have the D rated just for temporary emergencies?

[bob caldwell]

Google lug nut pattern...D for a spare, in my opinion, would work

[wmtire]

Originally Posted by sdsferraro

I have a 2016 Wildwood 27RKSS, it has ST205/75r15 tires.

Also the current tires,which only have about 150 miles on them, have C rated tires. I see better deals on mounted D rated than C rated.

Just to be clear on something that many outside the tire business get confused on is the difference between a "radial" tire and a ( "bias" tire sometimes referred to as a "diagonal" tire)

The main difference is the way the body plies are in the tire as a radial has them running across the radius and a bias/diagonal tire has them running at a bias or diagonal angle.

Now why this post. Your original tire is a radial as in the size ST205/75r15. The r between 75 and 15 means radial construction.

Now if you are perhaps looking at another tire that says ST205/75d15...... that d between the 75 and 15 means diagonal and is NOT the load range.

The load range will not be in the tire size, and is separate. Bias/diagonal tires are usually cheaper than a radial, which is possibly why you are seeing the price difference if confusing the d for a load rating instead of tire construction type.

Just letting you know.

[sdsferraro]

Thank you. Yes that is what I was thinking D load range was. Glad you cleared that up for me.

[wmtire]

Originally Posted by sdsferraro

Thank you. Yes that is what I was thinking D load range was. Glad you cleared that up for me.

You are very welcome ,as I deal with this weekly in my tire business.

As you are perusing tires to buy, now that you know there are bias/diagonal construction types vs radials, you want to look at either ply ratings or Load Ranges...... both of which or only one may be listed on the sales page.

The following applies to either radial or bias/diagonal body ply construction types.

A Load Range C tire is a 6 ply rated tire (usually 50 psi max pressure)
A Load Range D tire is an 8 ply rated tire (Usually 65 psi max pressure)
A Load Range E tire is a 10 ply rated tire (usually 80 psi max pressure)

[SidecarFlip]

Originally Posted by bob caldwell

Google lug nut pattern...D for a spare, in my opinion, would work

All it takes is a ruler and measure across the studs diagonally. That will give you the correct spacing 4.5, 4.75 or 5.

[Brother Les]

when the time comes to replace your tires, go from the C rated to the D rated.

[debit]

Thank you WNtire. Very helpful.
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Ram2500 4x4 diesel 6 speed manual
FR 251RKS

[wmtire]

One last thing is when you look at ST tires and their specs, you may see Load Range abbreviated to LR....... And Ply Rating abbreviated to PR.

Example would be LR D, or 8 PR.

[jeff64]

Take a look at the yellow sticker on the LF corner of the TT. I'd swear mine not only states the wheel size, inflation and load but the B.C. as 4.5 as well. Look closely! I've got the (in) famed st205-75R14c
If you go to the etrailer.com site you might find a clearer explanation on the measurement for the bolt circle, if you have to go that route since you can get tire and rim from them

[wmtire]

Originally Posted by SidecarFlip

All it takes is a ruler and measure across the studs diagonally. That will give you the correct spacing 4.5, 4.75 or 5.

To clarify a little on Daryl's post, if measuring an even number of studs (4, 6, 8) then you measure the studs directly across from each other, center to center.

If measuring an odd number of studs (5,7), then you measure from the center of one stud across to the outside edge of the either of the studs diagonal to it.

This diagram will help