Wheel cover off

The impact on gas mileage will probably be negligible and depend on where you drive. I can see possibly being a slight hit if you do a lot of highway driving where the aerodynamics play a bigger role, but if you mainly commute on surface streets where your speed will rarely get above 45 mph, I doubt you'll see any difference.

Check the Center Cap Thread for a good deal on the center Caps off eBay...

 

You will not notice a differnce with the wheel covers off. You can increase your MPG's by adding more air in your tires. It can make a 5MPG differnce. I run 49/47 PSI.

 

I noticed almost all on the forum add to the recommended pressure in the tires?
If this enables better mileage why is it that Toyota doesn't recommend it?
Any ideas?

 

The tires have a max rating. Going over that would be a liability to both Toyota and the tire manufacture.

Another option is to equipped the car with harder tires. This might produce a ride that is not a comfortable. I am ok with the ride at 49/47. Some might not be.

 

Like others have said it will had to see drop in mileage.

Before: 7950 miles, display 57.9mpg, computed 55.7, over all.

Mud flaps add wheel covers removed.

After: 8078 mile, display 57.6, computed 55.8, over all.

But I had 10% more highway driving in the "after"

Tires at 38F/36R

 

It won't degrade MPGs by more than a few tenths. I removed mine, and saw no difference. I get in the low 60's MPG.

One would think that a bigger impact would be the sun roof? Creates some air turbulance/drag. I always travel with mine tilted, and yet, have not seen a drop in my MPGs ...that I can measure.

Now, with all this said, anything that impacts air resistance/turbulance is going to have a bigger impact the higher the speed. So, if I was always travelling at 75mph, then I might see some impact. But my highway speed is closer to 60 mph, and rarely during my comute, do i get the opportunity to go this fast...usually a LOT slower.

 

Remember the Ford Exploder/Firestone mess? Ford's recommended tire pressure was below optimal because they wanted a cushier ride, which led to tires overheating and blowing out, which in-turn lead to rollovers! An under inflated tire will get hotter than a tire inflated to the max rating on the side wall. The lower the pressure, the more side wall flex, and more heat. The heat is the culprit, not the pressure.

Many car manufacturers recommend a lower than optimal tire pressure so they don't get complaints of a harsh ride. The max rating on the side wall is the Max Cold Tire Pressure, there is built in tolerance for increased pressure as the tires heat up going down the road. As long as you don't exceed that max tire pressure you will be fine.

 

I have seen a 2 MPG decline since removing our a couple weeks ago (after 4 weeks of ownership). It could be coincidental or my wife's lead foot.

The 2 MPG is worth it not to have to look at those hideous hubcaps though.

 

I got a 2 mpg improvement when I took mine off. That had nothing to do with the hubcaps either.

 

I took my hubcaps off and never ever saw a difference. I also put on the small mudflaps and saw no hit in mpg at all but definitely see way less mud and junk up on my doors and panels etc when it rains.

 

Is this a real question or are you simply waiting to see the debate this issue often ignites?

IMO auto manufacturers offer a recommendation based on what they determine is the best compromise between Mileage, Safety,Stability and Ride Comfort...and maybe other factors I'm not even aware of...

An auto manufacter is not going to offer a recommendation that exceeds the Max as defined by the Tire Manufacturer.

As a result of learning about hybrids, and hypermiling techniques and research into this area, I feel comfortable with my non-hybrid in exceeding my auto manufacturers recommendation but I would never feel comfortable exceeding the tire manufacturers Max.

As a consumer, I think you can determine what you feel is the best PSI to maintain. I certainly would never keep my PSI below the recommendation of the manufacturer but any increase needs to be done with a personal subjective evaluation as to ride comfort, stability and also gas mileage benefit. Since desires in these areas are going to differ from individual to individual, there is no real clear answer.

Specifically to answer your question. Why doesn't Toyota recommend this? Well all of the above...plus if they are setting a recommendation it HAS to be static. They can't really say..."This is what we recommend but you can add or subtract to it..." can you imagine the potential mess that would create?

 

Without any real data collected in a semi-scientific way, I would not attribute your MPG change to the wheel covers. I would be willing to bet a large amount of money that your loss is the cause of something other than the wheel covers being removed.

So feel good about your choice to allow your wheels to go streaking through the neighborhood!

 

Anyone have any updated input on this? I prefer the look of the wheel covers off, but do not want to sacrifice a significant MPG hit, if there is one. Some people are reporting no change, tho I'm not sure what their daily commute& MPH average are. I've read some posts from folks who state that at highway speeds, MPG can get his by an average of 4-6 less. My daily work commute takes me down a country highway where i average about 60 MPH for about 20 minutes (each way). Insights/feedback/actual reports from the road are appreciated!

 

That is crap. People really don't know how to perform even semi-scientific tests with regards to MPG and changes to their Prius that could affect MPG. There have been no real tests for MPG changes with and without wheel covers let alone ones in which the result of removing wheels covers produced a 4-6mpg loss.

If you like the look then take the covers off and be happy.

 

Concur.
I haven't seen or heard about a measureable ding in fuel economy by removing the covers.
If you're a dedicated hypermiler that has blocked grills, stiff tires, a never-used HVAC system, AND you drive a bunch of highway miles, you might be able to quantify as much as a one-point-something MPG delta with covered alloys---but I personally believe that that's swinging after the bell.
If you think that the plasticky wheel covers are unattractive, then live a little!!!
Take 'em off!

 

Last tank, I was achieving 58-60 mpg. Midway through the tank I took them off and I was only getting 53-54 mpg. Ended up at 57 mpg for the tank. These are MFD readings, using both trip meters. Take that for what it's worth.

I'm going to put my wheel covers back on real soon and see if my MPGs differ any.

 

Again, this is useless information unless you describe at least the following conditions for both tanks:

Weather
Average Temperature
Wind patterns during each trip
Road conditions (road surface type and if water is present)
Average speed traveled
Tire pressure during the entire test
Driving procedure
Number of trips, average miles travel per trip and cold start vs. hot start info
Topography of roadway (if topography changed even a little the results are void)

As you can see, there are a large number of variables one has to look at before they can even attempt to come to a conclusion that their mpg has changed due to the removal of wheel covers.

I'll make it easy for anyone contemplating performing and actual test for this. Set it up under in a controlled manner and use a long stretch of flat road where traffic will not interrupt your testing. Doing this test over a full tank will create WAY too many uncontrolled variables.

 

I absolutely agree with your assessment. However, please note that I mentioned "take that for what it's worth" and why mentioned I'm planning on doing more tests. I'm aware of the requirements to have a valid & controlled test. I was just trying to provide op with the info he requested. Also I posted to see whether other people's experiences are somewhat congruent to mine.

I can't minimize all variables, but I did use the same tank & route.