Toyota Prius wheel covers?

I noticed today, that the Prius has alloy wheels which are covered by a plastic wheel cover. Why is this?

Reply to
tangerine_sedge
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:I noticed today, that the Prius has alloy wheels which are covered by a : plastic wheel cover. Why is this?

Lower coefficient of drag.

Mack

Reply to
M. MacDonald

In that case, why not just design the alloys in one piece like that?

Reply to
tangerine_sedge

Steel is cheaper and often (bizarrely) as a wheel it is lighter.

mrcheerful

Reply to
mrcheerful

I'll take a common-sense guess at the answer: Because a plastic wheel cover and a generic alloy wheel costs a lot less to engineer and manufacture than a model-specific alloy wheel (design, engineering, moldmaking, safety and structural testing, production foundry tooling, machining, production QA testing...) - There are not going to be enough Prius per year made (50,000 cars X 4) to properly amortize those costs. So they use a generic alloy wheel and spend a little on a custom mold for an aerodynamic wheel cover.

You can make the wheel lighter and stiffer if you are not concentrating on aesthetic design - it takes more material to cantilever all the loads from the rim (bead seat) out onto the flat dish face of the wheel, and then back into the lug nut mounting face - adding gussets to spread the load also adds weight. Conventional 'dished' wheel design keeps those loads closer to the center-line of the wheel and mostly eliminates the cantilever loads. And since the Prius uses the service brakes sparingly (regenerative braking) the wheels and covers dont need ventilation holes.

And there are financial considerations for the car owner, too: If you wipe out a plastic wheel cover on a curb they are simple and (relatively) inexpensive to replace. If you wiped out a generic alloy wheel at the same time, it will be expensive, but not ridiculous. (I'm guessing they're borrowing a generic Echo alloy wheel out of the parts bins.)

But if you wipe out a specially made flat-dish aero face Prius Only alloy wheel against a curb, it will cost a small fortune to replace. And it will take them quite a while to hit the junkyards.

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Reply to
Bruce L. Bergman

Bruce,

thanks for your answer. I think you're probably right, it's covering an ugly looking, but lightweight alloy wheel.

I doubt if it's there to protect the alloy from kerbing - after all, if you damage an alloy where are you going to get a new one - Toyota? :)

Reply to
tangerine_sedge

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