Is it true that aluminum rims help with gas mileage, all other things being equal? I have heard that is the reason otr truck drivers prefer them.

Not to my knowledge. What they do provide is a more accurate round shape that eliminates "bounce" due to wheels being out-of-round or warped. I suspect OTR drivers like them because they look kewl...

They also reduce unsprung weight - important on sports cars (allow the suspension to react more quickly), but unless one is in Le' Grand Prix de Mammoths, not a factor in RVs.

Inner wheels on duals have to be steel anyway...

quote:

Originally posted by Mary Ray:
Is it true that aluminum rims help with gas mileage, all other things being equal?

Yes.

But:

1. All other things are seldom equal.

2. The effect is miniscule. Perhaps unmeasurable, outside of a lab.

Lighter wheels will absorb a bit less power during acceleration and truer wheels will absorb less power during cruise.

They do indeed look kewl. Wish I had a set. I have almost bought a coupla SOBs just to cannibilize the wheels and resell the coach.

quote:

Originally posted by bill h:They do indeed look kewl. Wish I had a set. I have almost bought a coupla SOBs just to cannibilize the wheels and resell the coach.

OTOH, stainless steel wheel covers are much easier to keep looking good. That said, my Lexus has alloy wheels, but they're a matte finish. My van has 'em (replaced warped steel wheels, and cheaper that steel), and they also have a matte finish, but always look ugly.

I've had stainless liners and Aluminum wheels and give me the stainless any day.

The main reason truckers use aluminum is weight. With the number of wheels they have it can make a difference of 2-400 pounds and that can turn into money.

quote:

Originally posted by Rusty:


Inner wheels on duals have to be steel anyway...

I have aluminum wheels and they are aluminum inner and outer.

Only requirement that I know of is there are special inner attachment bolts for use with aluminum wheels if mounted inner.

I wish I could find steel 19.5" X 7.0" or 19.5" X 7.75" in the 6 bolt Budd pattern!

quote:

Originally posted by Rusty:

Inner wheels on duals have to be steel anyway...

Rusty, "Ugly Betty" has all six wheels that are 22.5 inch Alcoa Aluminum, including the inner duals?????
Nick

For 16" Alcoas, they show different part numbers for "inner" or "outer" wheels, the only difference being the degree of final finishing on either the convex or concave side of the wheel, i.e.: My barth takes 2 "outies" for the steer tires, 2 "innies" for the outside duals and 2
I-don't-cares for the inside duals (unlike a GMC motorhome with single wheel tandem arrangement that would need six 6 "outies" to have the finished side exposed...)

Strange - when I was looking for replacement wheels for my SOB, Alcoa's website specified inner steel wheels here; I see now that applies only to the 16", which is what I was after.

Another oldie but goodie thread..

the conversation re: inner steel wheels on rear duals is of interest. I've have to query my mechanic on what I have inside rear..Outside are Alcoa's.. This conversation deals with 16/19.5" wheels.. Any different approaches if you have 22.5" wheels ? Steel wheels preferred or ...?

heres my rear outside rear wheel..Pardon the photo manipulation for my avatar..

I can not address 22.5 wheels as my Breakaway has 19.5. However, it appears that the 6 bolt Budd pattern Alcoa is getting very hard to find. 19.5 6 bolt Budds are no longer available. Metric 6 bolt Budds are available but will not bolt to our bolt diameter. Can't say for sure 6 bolt Budd 22.5 wheels are still available from Alcoa.

I had 4 steel wheels built all for the rear because I wanted to run 245R70 19.5 and they require a wider wheel then even the Alco 6 inch wide wheel.

When I bought my Breakaway, it had all 6 wheels Alcoa. First they did not have the correct inner lug bolts, they are supposed to have an extension beyond the flange to help located the wheel. Second, even though I FIRMLY stated to tire installers that they were not to use an impact wrench, they did, result-----2 cracked wheels-----JUNK!

Now at least I have spare Alcoa for the front.

I did run steel inners and Alcoa outers with 225R70 195 on the rear for awhile and could tell no difference when all 4 rears were Alcos.

With over 15K lbs weight on the rear, the additional unsprung weight of steel wheels is not a factor with no noticeable change in ride NVH.

I know this doesn't address your 22.5 issue, but if I were you, I would definitely use steel inner and save the Alcoa!

Thanks MW, anyone have a source for HD steel inner wheels that will work with Alcoa's on the outside in a 22.5 configuration..?
are the outside and inside Alcoa's the same wheel?

quote:

Originally posted by Rusty:

Inner wheels on duals have to be steel anyway...

Who says? All six of my wheels are aluminum. In fact I rotated the inside rear to the front a few years back.

quote:

Originally posted by Mike/Cindi W:
Another oldie but goodie thread..

the conversation re: inner steel wheels on rear duals is of interest. I've have to query my mechanic on what I have inside rear..Outside are Alcoa's.. This conversation deals with 16/19.5" wheels.. Any different approaches if you have 22.5" wheels ? Steel wheels preferred or ...?

Mike you have the Gillig Chassis. I have 6 aluminum wheels. I am the only one here that rotated tires. You can rotate inside duals to front, or outside duals to the front, but on the opposite side.

Looks to me, like a new Kitchen sink drain at the big box store. They never stay that shiny.