Extra weight of Moab wheels & spacers?

[fallacist]

I wanna swap my 15" cragar soft 8 steelies out with some lighter aluminum ones. I found a prettttty sweet deal on some 17" moabs off a '11 wrangler.

I was all game to switch everything up (also swapping skinnier tires in like (285/295)/70/17 from 33x12.5) then realized the added weight of the spacer/adapters (4lb ea) probably offsets most of the weight loss by switching to aluminum, not to mention the extra metal weight going from 15" to 17".

So if I'm shooting for lighter weight and skinnier tires, is it worth finding a 5 on 4.5 wheel (with appropriate backspacing) to avoid the adapter/spacers?

 

[PhotoJared]

In all reality it's all heavy. Now the spacers will affect your unsprung weight differently than the wheels because it's closer to the center of the wheel.

Personally I wouldn't worry about the weight unless this was a track car

 

[Hypoid]

I think the big weight savings is in the tire itself. The taller tire/wheel combo that I put on actually has a shorter sidewall. Not to mention, the spokes make good handles when you have to take a wheel off the Jeep.

 

[fallacist]

Since going to 33x12.5, I haven't appreciated the lesser braking quality, burning through ujoints and the loss of mpg and power. Those traits are well known, but I had to experience them for myself to realize I wasn't a huge fan.

I want the diameter of a 33" due to my lift and cut fenders, and the advantages that a larger diameter tire offers, but after driving in snow with them last winter, I want to go the pizza cutter route (33x10.5). Plus the XJ crawls well enough for what I use it for in the mountains and desert, that I don't really feel the extra width of a 12.5 vs a 10.5" tire is necessary.

Are you saying any "gains" I make will be going from a 15" wheel to a 17" wheel and eliminating those 2" of tire sidewall? I've read that your wheel weight, the rotating mass or whatever it's called, has a significant impact on those things I mentioned in the first paragraph.

At the end of the day, I wont see the difference between steelies and 33x12.5x15 vs aluminums (moabs?) and something like 285/75/16 or 285/70/17? (33x11.2)

 

[cal]

As stated above, the weight of the spacers is a non issue, as its so close to the center of your rotating mass.

There would be some weight savings. You probably won't notice any real difference, though.

How are your axles geared? thats where you'll notice it.

 

[fallacist]

Haven't regeared- I know, I know.

I wanted to hit discount tire up for their labor day sale this week. $70 on Coopers (although I'd prefer duratracs), and another $160 rebate on 4 tires. $230 off 4 new tires isn't a bad deal.

So at the end of the day, I wouldn't notice a difference worth doing going from 33x12.5 on a 15" steel wheel, to the equivalent of a 33x10.5 on a 17" aluminum one?

 

[cal]

I can't say that you wouldn't, but you probably wouldn't.

I switch back and forth between steel and alloy wheels on my rig and don't notice a difference - and I can *guarantee* you I'm pushing harder than you will be.

 

[dan1977p]

I haven't appreciated the lesser braking quality, burning through ujoints and the loss of mpg and power.
You'll regain most mpg and torque by regearing.
You'll never gain back braking performance without upgrading the braking system or going back to stock diameter tires. Most of the mass for the tire is in the tread and that is generating most of the rotational inertia so not reducing overall diameter of the tire will net little gain stopping or going. It's an easy upgrade to get a dual diaphragm brake booster and upgrade to black magic pads. If you want ease of maintenance, change your rears to discs as well but a properly set up drum works just as well.

 

[techno1154]

My XJ is geared 4 .10 and have been that way since 2004. I replaced the OEM wire wheels that had 31 X 10.5 X 15 BFG AT KO tires with some JK Moab takeoffs Goodyear wrangler 255 X 75 X 17 and moved my mileage from 250 miles per 15 gallons to 300 miles per 15 gallons. The only negative I noticed is that the Bilstein 5150 do not like the larger tires on the front resulting in wheel hop on bumpy roads.