Hubcaps Removal how much MPG lost?

Depends where you are driving and weather conditions. Highway a couple miles per gallon at most. In town less effect.

 

Statistically insignificant as best we can tell. Maybe a few gallons.... Over the lifetime of the car.

 

You'll probably see a small mpg hit only if you do lots of highway driving, so it really depends on your driving pattern.

 

Statistically insignificant for me here in hilly Vermont.... and I drive a TON of highway miles. But note my average in my sig... I can't compete with the warm weather flatlanders in lifetime average.

 

Had them off for 60,000kms and haven't noticed any difference. I'm not doing as much freeway driving now and my consumption has dropped from 4.8 to 4.6 l/100kms (49 mpg to 51mpg us gallons.)

 

I took them off 20,000 miles ago, and have not noticed any reduction in MPG.
The bit about the wheel covers affecting MPG is a myth.

 

None!!!

 

Just because you've not noticed a reduction based on your driving pattern doesn't make it a myth. Several members have indeed reported a reduction.

 

In the healthcare business, we call this "clinically insignificant"

Maybe...maybe...if you drive 100 mph 24/7 you might notice .01 less mpg

 

Shhhh don't tell anybody.....

The hubcaps are the secret sauce of the Prius's great mileage. I took mine off and the gas mileage immediately dropped to 18 mpg. I put the Prius hub caps on my Ford F150 and the truck's mileage immediately went up to 50 mpg.

Keith

P.S. Anybody want to buy a slightly used bridge???

 

Maybe based on your own driving pattern, but there are members who've reported a mph hit as great as upsizing the wheels.

It's best to do the test yourself. If you see no change, then leave them off.

 

No one has ever demonstrated here, any statistically significant difference one way or the other. I wish Toyota would give us any data they had on the issue.

In the mean time, do what you think looks best.

 

Makes no sense. And how do you come up with the figure of .01mpg @100mph? seems kind of arbitrary.

So one would have to ask, why does toyota go to the trouble of adding rotating weight to a wheel? Why do they go to the expense at all of manufacturing and installing these covers? Wouldn't you assume that the aerodynamic efficiency offsets the added inertial inefficiency?
Toyota continues to refine this vehicle, and lower it's COD, they would not add these for cosmetic purposes, there must be an actual COD benefit of having them there.

 

Neither have the people who are comparing 15" vs. larger wheels. Haven't seen any real statistics from them either. All they're doing is "I'm getting X mpg with this and Y mpg with that" over a selected few tanks.

 

How long have you owned a Prius? How long have you been tracking mpg in the Prius?

We can banter back in forth with hypotheticals and why Toyota put them on but the fact is no one has been able to measure a mpg change with or without the covers. This has been talked about for years with the GenII and then again with the introduction of the GenIII. If you think they make a difference and you like the look then keep them on. If you think it looks better sans covers then take them off. Arguing about them is a waste of time unless you want to be the one to produce some serious A-B-A data so we can lay this to rest.

 

Excuse me. 5 years worth of swapping back and forth between 15s and 17s for thousands of miles at a time is not "a selected few tanks". IT doesn't take rigorous testing procedures to measure the difference when performed repeatedly in quick succession.

 

Yet we have the unproven theory that the factory 17" wheels minimize the mpg loss partly because of aerodynamics. I don't think we can lay this to rest because of the varying driving patterns. There have been members here who claim a reduction in fuel economy with the covers off, after doing their own tests.

I'm not disputing that. Just saying they've not shown statistically significance, which requires performing actual statistics. Consistently demonstrating a difference is meaningless unless you show the actual statistics

 

Why not? They added plenty of other things for cosmetic purposes, which can't possibly do anything but hurt mileage.

Any comparison of aerodynamics versus inertia would depend drastically on driving habits.

The truth is I don't know why they put them on, and neither do you.

 

Yup!