Fuel mileage and the huge mud flap across the back

hershey wrote:
Just thinkin'.
I see a lot of conversions to the tractor trailer rigs where the distance between trailer wheels and tractor is now skirted to decrease the effect of wind drag and increase fuel mileage. It must have some factual positive effect because of the larger and larger number of them becoming visible.
Is there any benefit to reducing drag with the large mud flaps on a MH? Or does that flap increase wind drag?
Has anyone found any perceived factual info that encourages or discourages the use as a fuel mileage enhancement????

Back to topic. By now in the computer age there would be some type of program "free" anybody could use. Maybe scan your pic in of your rig and have a way to measure resistance or how much horse power/gearing is needed to overcome resistance.
Maybe plan B just go with the wind http://hint.fm/wind/

I think they should outlaw the large flaps that are covered with bright chrome.

It's like having a mirror on there and can be quite irritating when the sun hits it right.

sowego wrote:
Our flap came off and we've not replaced it yet. I don't think it affected our mpg.

There was a topic on here a while ago about the large mud flaps would allow more damage to a towed vehicle. With idea in mind...we are opting to go without a large mud flap.

A mud flap that scrapes the ground will add to toad damage. If you notice an increase in scrape marks on the bottom of the mud flap, check ride height!

One that is clear of the ground will reduce toad damage. The amount of damage reduction depends on lots of factors, including effectiveness of mud flaps just behind rear wheels, distance from rear wheels to back of coach, etc.

Our flap came off and we've not replaced it yet. I don't think it affected our mpg.

There was a topic on here a while ago about the large mud flaps would allow more damage to a towed vehicle. With idea in mind...we are opting to go without a large mud flap.

When in college (a tech one) a fellow student did studies on fuel savings for a local trucking company. His biggest savings was (?shrink?) wrapping the underside of the trailer, that cut down on the wind resistance. I'm guessing the current side flaps are achieving the same effort with much less effort.

IMO, the class A industry has to address the MPG issue, or suffer the slow decline for new customers. Salaries have remained stable over the years, MPG for a MH have remained stable, yet cost of fuel has gone up by a factor of 3 to 5 (or more) times. What's wrong with that picture.

Bumpyroad wrote:
this thread reminds me of something that has bugged me for years. Why is the 53 ft. written on the sides of these units? I assume that 53 ft is the maximum length or something but what purpose does posting it have? just wondering. I mean, if it is not posted do they measure the unit at weigh stations?
Sort of like the overhead clearance lights on pickups, other than a potential spot for water to leak in, why?
bumpy

X2
There is also a segment of our population that likes to inform other drivers that they have 24” wheels on their retired cop car.

paulsang wrote:

ArchHoagland wrote:

Johno02 wrote:
Biggest reason for seeing the side flaps is that they are required for trucks in California. They are OK on the road except in sidewinds, where they increase the side surface, and multiplying the side wind effect. That is what our family driver says.

Required in California? Could you elaborate on that?

Side flaps. CA requires them. Not really something that will help a MH driver.

California requires them on certain trailers. Trailers over 53' long for example. It is a California CARB (Air Resources) law. http://www.arb.ca.gov/cc/hdghg/hdghg.htm

and to the OP, that big rock crusher mudflap across the back of motorhomes has been long debated around here. There are those who say we need them and those who say we don't. And you do need some type of mud flaps behind the rear tires, required by most state laws. Do they affect fuel mileage??? Not that you are going to be able to measure!

ArchHoagland wrote:

Johno02 wrote:
Biggest reason for seeing the side flaps is that they are required for trucks in California. They are OK on the road except in sidewinds, where they increase the side surface, and multiplying the side wind effect. That is what our family driver says.

Required in California? Could you elaborate on that?

Side flaps. CA requires them. Not really something that will help a MH driver.

Johno02 wrote:
Biggest reason for seeing the side flaps is that they are required for trucks in California. They are OK on the road except in sidewinds, where they increase the side surface, and multiplying the side wind effect. That is what our family driver says.

Required in California? Could you elaborate on that?

Biggest reason for seeing the side flaps is that they are required for trucks in California. They are OK on the road except in sidewinds, where they increase the side surface, and multiplying the side wind effect. That is what our family driver says.