New Rims for Taza's Forester

I have the heavy steelies... and although I got the 4 of them for 50$, might be worth paying a bit more for lighter ones that will make me save on fuel economy... I'll be on the lookout for these, good idea!
 
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A rule of thumb I read somewhere was an extra 1kg weight on a wheel is roughly equivalent to an extra 10kgs in the vehicle.
 
^in my experience swapping between 215/65R16 AT tyres on steel rims to 215/60R17 HT tyres on alloys, I get around 6-8% better economy on the alloys.

Calculated with average of around 40k kms on alloys and 18k kms on the steels...

Pedro.
 
I weighed the OEM steel rims I bought for my trailer along with the OEM matching alloy I bought for the spare in Roo2.

IIRC, the steelies weighed in around 11+ kgs each, and the alloy at about 8 kgs. I have this written down somewhere, and will try to remember to check these figures tomorrow.

That's a huge difference in both the inertia and the unsprung weight.

Overcoming inertia is the main user of fuel. This is why fuel consumption is far higher with start/stop driving than with highway touring.

Manufacturers have spent a large fortune in reducing unsprung weight, as this attribute has a huge effect on the handling and comfort of any vehicle.
 
Venom said:
A rule of thumb I read somewhere was an extra 1kg weight on a wheel is roughly equivalent to an extra 10kgs in the vehicle.
Click to expand...

Ratbag said:
IIRC, the steelies weighed in around 11+ kgs each, and the alloy at about 8 kgs.
Click to expand...

Going on these figures, 3kg per wheel x 4 wheels x 10:1 ratio = approx an extra 120kg of weight in the car. That'l make a big difference to fuel economy! Not to mention braking & roadholding...
 
Plus the spare rim as well and you could make that equivalent to 150kgs.

Those Audi rims I posted the guide for are 5.8kgs. So with those you can make that 5kgs lighter per rim x 10 = 250kgs including spare equivalent weight saving over a set of steelies. Considering when you're offroading a car is generally loaded to the gunnels anyway, something like a lightweight rims is going to make a big difference to the power and economy of the car offroad. I think steelies are a bit of a false economy myself. They bend easily, heavy, **** offset.
 
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Gidday All

Found where I wrote the figures down ... Here:
https://offroadsubarus.com/showpost.php?p=40850&postcount=14

:ebiggrin:

I have weighed the steel 16x6.5 OEM Subaru rims I bought for my trailer (not the different spare, which is a little lighter than the on-car steel rims; but not a rubbish space saver spare), and the bare alloy rim I bought to replace the steel spare that came with Roo2.

Steel rim (bare) = 11 Kgs
Alloy rim (bare) = 8 Kgs

So 3 Kgs the difference in the rims.

One also needs to factor in the differing weights of different tyres, and potentially very different rolling resistance of different tyre types and construction.
 
(Taza - let me know if I'm hijacking your thread! :raz:)

Ratbag, your post you linked makes me wonder - perhaps I should get the alloy H6 16in wheels I've been offered for 80$ (pic below) and keep them mounted with standard summer tires for the 80% driving I -sadly :lol: - do in the city (40km commute everyday for my internship this summer...) and just swap them for the heavier AT tires for the occasional (2 times a month, hopefully?) times I head out in the backcountry?

Does anyone here do this?

Subaru-Legacy-Outback-2002.JPG
 
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Gidday Fly

At $80 for the set, that's like stealing mate!!

Is that with tyres?

Don't forget to buy a matching spare.
The weight difference will make more of a difference to the strain on diffs and tranny than all the BS that Subaru go on with in the Owner's Manual about having the same kind of tyre with the same wear pattern as a spare!!
Then they supplied a steely as a spare in Roo2 ... :surprised: :eek: :shrug:
 
Out of interest, my AT tyres and rims weigh 23kg each.

The HT and alloys are 2kg lighter at 21kg each...

Weighed them last night as I was swapping the ATs out. Bad note is I found both my rear bearings were stuffed...
 
^ That would account for the lesser difference in weight.

I would expect the 17" alloys to be closer in weight to the 16" steelies than 16" alloys are to 16" steelies ...

Tyre weight would probably be similar, with the larger wheels being a lower profile, so possibly proportionally a bit 'lighter'.
 
Keep discussing guys. I don't mind. I have found that after a week(tomorrow) that I have gained another 100km to the tank, I'm now reaching 300km to a full tank... yay
Braking was improved dramatically along with cornering and well a little with accelerating.
I did however loose over 4kg a wheel swapping to alloy 15" rims.
 
^ ^ That's a bugger about your wheel bearings, Pedro.

As to the weight of rim + tyre, I'll drag out my 215x60 16" alloy OEM spare tomorrow and weigh it. Need to check the pressure in it anyway.

^ Taza, that's one hell of an increase in fuel economy, even with your shagged donk - 50%! It would probably make less of a difference if your engine were running well, because less of a strain, with more efficiency, but still ... I sure shows how much effect having the lightest rims and tyres can have, while still remaining strong enough for our fairly mild off-roading.
 
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