Do you guys carry six 21mm acorn type lug nuts for the spare steel wheel?

[1engineer]

A great question. I have neither any documentation nor calculation to back it up. My 2014 Camry LE came with steel rims and had acorn lug nuts. I bought SE rims for my Camry and had to buy a set of mag type lug nuts. As far as I can tell (with my untrained eyes), the spare steel rim looks same as my steel rims. I am not sure what calculation I can perform (even if I were smart enough to do that). The mag type lug nuts are the best fit (IMHO) for Toyota OEM alloy rims but not necessary true (IMHO) for the steel rims. Coversely, acorn lug nuts will not be best (IMHO) for Toyota OEM alloy rims. I know there is no math behind this but please try a mag type lug nut and acorn type lug nut on a steel rim and tell me which lug nut type you prefer holding on the wheel. If you know how to perform calculation, I am willing to give it a try but you will have to go easy on me.

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I wrote a short article here awhile back when some members had studs break from over torque. A mechanical fastener, in this case a nut and bolt, depends on clamp force and length of thread engagement. This assumes the material spec is adequate of course.

Clamp force is measured in lb-ft of torque and length of engagement is simply that. Bottom line is if the nut is of correct material, has the proper thread engagement, is able to seat firmly against the wheel with full shoulder contact and can be torqued to published values then it won't matter which nut you use, acorn or open.

I will try to find my early post to show a sample of how proper torque calculations are done. This also includes thread stretch.

Edit: Here's is one place http://www.toyota-4runner.org/5th-gen-t4rs/95630-broken-stretched-lug-stud-issue-solved.html I discussed the lug bolt torque and lubrication. I did another full write up but cannot find it at the moment. Oh, post #11 is my input.

 

[SierraMare]

I have an article (a documentation) from Toyota (it was dated 2004) - see page 8 about interchanging mag and conical type lug nuts.
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I wouldn't worry about using special lug nuts for the OEM steel spare wheel. If there was a problem with using the OEM lug nuts from the alloy wheels for the steel 4Runner spare, I think Toyota would have provided special lug nuts with in their tire change kit, or would have noted something in the Owner's Manual about limited driving on said spare. Liability concerns would dictate this if necessary.

Also, from your link, page 13, I think Toyota is aware of when different lug nuts are needed:
"• After installing a set of custom wheels onto the customer’s vehicle, place one-wheel’s set of original Toyota nuts in a Ziploc bag and store this in the vehicle (in the original Toyota vehicle tool kit, next to the spare tire or jack, etc.). If the customer ever needs to install the original Toyota spare wheel/tire in an emergency, he or she will have the correct fasteners, since the fasteners that are used with the after-market wheels may differ in length or style from the OE."

 

[Jetboy]

Just to clarify if anyone doesn't know -
Toyota oem lugnuts are designed to have a conical seat profile so you can use them with the steel wheel. Of course your OEM lugnuts work with the steel spare. I tend to use the spare about once a year.

IF they looked like this: you'd be in trouble

 

[NorthwoodsRunner]

I wrote a short article here awhile back when some members had studs break from over torque. A mechanical fastener, in this case a nut and bolt, depends on clamp force and length of thread engagement. This assumes the material spec is adequate of course.
Clamp force is measured in lb-ft of torque and length of engagement is simply that. Bottom line is if the nut is of correct material, has the proper thread engagement, is able to seat firmly against the wheel with full shoulder contact and can be torqued to published values then it won't matter which nut you use, acorn or open.
I will try to find my early post to show a sample of how proper torque calculations are done. This also includes thread stretch.
Edit: Here's is one place http://www.toyota-4runner.org/5th-gen-t4rs/95630-broken-stretched-lug-stud-issue-solved.html I discussed the lug bolt torque and lubrication. I did another full write up but cannot find it at the moment. Oh, post #11 is my input.

I see your points. What it bothered me was the contact surface area. I know there is conical seat profile on Toyota OEM mag lug nuts but my untrained gross visual tells me that acorn lug nuts seem to give more contact and less chance for mistake. Interesting the owner's manual tells you to torque it at higher setting: 82 lb-ft for steel vs. 78 lb-ft for aluminum.

 

[PCMSF]

Also, from your link, page 13, I think Toyota is aware of when different lug nuts are needed:
"After installing a set of custom wheels onto the customer’s vehicle, place one-wheel’s set of original Toyota nuts in a Ziploc bag and store this in the vehicle (in the original Toyota vehicle tool kit, next to the spare tire or jack, etc.)."

Thanks for confirming this, just picked up a set of 6 OEM 4Runner lug nuts on eBay.

 

[gm350reratliff]

I wouldn't worry about using special lug nuts for the OEM steel spare wheel. If there was a problem with using the OEM lug nuts from the alloy wheels for the steel 4Runner spare, I think Toyota would have provided special lug nuts with in their tire change kit, or would have noted something in the Owner's Manual about limited driving on said spare. Liability concerns would dictate this if necessary.

Also, from your link, page 13, I think Toyota is aware of when different lug nuts are needed:
"• After installing a set of custom wheels onto the customer’s vehicle, place one-wheel’s set of original Toyota nuts in a Ziploc bag and store this in the vehicle (in the original Toyota vehicle tool kit, next to the spare tire or jack, etc.). If the customer ever needs to install the original Toyota spare wheel/tire in an emergency, he or she will have the correct fasteners, since the fasteners that are used with the after-market wheels may differ in length or style from the OE."

Since I have aftermarket wheels I do just that ^^^

 

[NorthwoodsRunner]

Thanks for confirming this, just picked up a set of 6 OEM 4Runner lug nuts on eBay.

This is awesome! I really enjoy a civil discourse such as this and ultimately helping someone or educating myself in the process.

 

[JeremyB]

I see your points. What it bothered me was the contact surface area. I know there is conical seat profile on Toyota OEM mag lug nuts but my untrained gross visual tells me that acorn lug nuts seem to give more contact and less chance for mistake. Interesting the owner's manual tells you to torque it at higher setting: 82 lb-ft for steel vs. 78 lb-ft for aluminum.

If the ID is the same (bolt dia), the angle is the same, and the OD is the same (hex dia), then how is the contact area different?

Steel/Steel has a higher coefficient of friction than Aluminum/Steel, so you'd want a higher torque on to achieve the same preload.

 

[NorthwoodsRunner]

If the ID is the same (bolt dia), the angle is the same, and the OD is the same (hex dia), then how is the contact area different?

If you look at the acorn lug nut (as shown in the first post) the taper section is a bit deeper compared to Toyota OEM lug nut. You are correct if the contact surface area is the same then there is no difference. I have not painted the lug nuts and compared the difference in the contact surface area. This is not hard to do. I agree with you in that you are not going to have any issue with OEM lug nuts with a steel wheel. I personally feel more comfortable carrying six acorn lug nuts in my glove compartment in case I have to deal with a flat tire in Montana or North Dakota.