Do mudguards hurt MPG at all?

I think there is an effect, bu most of us have found it to be in the .1 to .2 mpg range, not enough to worry about.

 

I only bought my Prius 2 1/2 months ago so don't have much to go on. I installed my mudguards a month ago, and thought I was getting 1 -2 mpg less, but with fluctuations in the temperature, not sure. The rear mudguards from Priue Chat are somewhat larger than the front ones. If you look under the rear, you will see that they protect very little. I am tempted to remove the rear ones.

 

I have the larger Euro Style and am still getting over 50MPG in normal driving with a short commute.

 

I have the smaller US version installed and see no mpg penalty. These flaps work well (keep muck off the side panels) and are not in the air stream as they align with the tires. They are a bit pricey for four pieces of blck plastic, but in the end, worth the money for the functionality. I also think they look good on my blizzard white gen III.

 

I fitted a full set to mine in the UK a couple of weeks ago, last week I had to drive up to Inverness in Scotland for work and back home, 840 miles and did not notice any drop off in MPG at all with them fitted. 600 of that 820 miles was at Motorway / Freeway speeds of 75 MPH on the GPS and I averaged 51.9 MPG (which I am actually really happy with)

 

I got mine installed a week ago and didn't notice any MPG change at all.
If there is a change of fuel consumption, it probably has to be measured by feet.

 

Installed the mud flaps form "priuschat shop" and removed the wheel cover at the
same time. There is no MPG change that I see over the last 3 mo. I have tracked
the routes I use every week {in town & back hi-way} with trip meter and tank fills.
Avg. 52/60+mpg before and after change.

 

I have a Prius 5 with the wider profile Tires, so I wish to prevent road salt, stones, etc from chipping the paint along the lower body sides, so I installed the mud guards front & rear. That prevents damage that is far more difficult to repair because repainting the car will be a lot more costly than any reduced fuel economy the guards might cause. I would not consider the economy of fuel in such a calculation to install the mud guard protection. I paid $ 750 to wrap the front bumper in paint protection. An ounce of prevention being worth a pound of 'cure' everty time.