Mag Wheels more efficient?

I don't remember any 'v's or Liftbacks coming with steel wheels. Only some 'c's do.

For best MPG, leave the covers on. They add some tiny increment too small for you to discern, it matters only to ensure rounding up to the intended EPA score.

For appearance, do as you please.

 

If you want to take off the plastic wheel covers you can purchase "hub caps" for the hole in the centre of the wheel either online, or from Toyota. The GII hub caps work fine. I'm using them. I removed the covers because they hold dirt on the wheel. Dirt plus road salt equals damaged wheel finish.

As far as efficiency goes, as posted above I doubt you could measure the difference in aero effects, but you -can- measure the difference caused by weight. The wheel covers are heavy. The hub caps are not. Of course, if you replaced the tyres with heavier ones then all bets are off.

 

Yes, and rotating mass hurts fuel economy more than mass in the body, so if you are going to save weight, the tires and wheels makes sense. (The brakes would make sense, except we need them to be able to absorb all the heat we might ever need to expose them to, so be very conservative lightening the brakes)

 

I not only removed my wheel covers but soon after I purchased NEW WHEELS (& tires).
I got 17" ENKIE RPF 1 wheels which are the lightest available that matched the 5 Model size, and Yokohama YK 580 tires in 215/50/17.
The plastic wheel covers look cheap and for the tiny "extra mileage" are not worth the weight.

With much lighter wheels I have:
1. less starting rolling weight to overcome
2. less rolling weight for braking
3. less unsprung weight for more responsive handling

And then there's the undeniable "custom coolness" factor. ;o)

 

No idea.

Didn't like the look of the plastic hubcaps. Took them off and found 16 inch "mags" and bought ebay plastic center caps.

Impressed with how clean the wheels have stayed, haven't cleaned them in 21k miles.

Never did anything to the wheels on any of my previous cars dating to 1960.

 

3½ pounds for my four of them.

My compromise:
Keep them off in local driving, which involves a lot of stops, starts, and hills, generally at relatively low speeds.
Put them back for long road trips, when speeds tend to be higher, so aero drag matters more.

 

BTW, I have my 4 original 16" wheels and tires (and wheel covers) for sale on this site.
Only 3,000 miles on the tires with 95% tread remaining according to Discount Tire.