Semi made me jealous of his wheel covers

[gumby79]

My ? Is what % of trucks using the *runaway ramp for emergency use only * on Donner Pass 40 miles down hill have the new wheelcovers i was told by a 45ydriver the thing ceeping whee covers off the road is end cost its cheeper to burn fule than replace tires because your drivers didnt check air pressure with the covers in place . As well reduced mpg from running low air

[101Volts]

Originally Posted by Baltothewolf

A lot of trucks in California rock the side skirts/moon disks/trailer tails. I talked to quite a few truckers over the course of me working in security at a truck gate. The gains are actually quite good from reports. One fellow I remember talking to said at 55mph he gained 3mpg increase, from 9mpg to 12mpg. It may not seem like much, but when you do close to 50k miles a year, the savings are enormous!

9 MPG = 11.1x Gallons per hundred miles

12 MPG = 8.5 Gallons per hundred miles

Per thousand:

9 MPG = 111.x Gallons per 1k

12 MPG = 85 Gallons per 1k

And ten thousand:

9 = 1,11x Gallons per 10k
12 = 850 Gallons per 10k

Yep.

[deejaaa]

Originally Posted by gumby79

My ? Is what % of trucks using the *runaway ramp for emergency use only * on Donner Pass 40 miles down hill have the new wheelcovers i was told by a 45ydriver the thing ceeping whee covers off the road is end cost its cheeper to burn fule than replace tires because your drivers didnt check air pressure with the covers in place . As well reduced mpg from running low air

what? didn't understand your statement.

[gumby79]

My question is has their ben an increase of trucks loosing thier breaks from extra heat buld up running covers . The rest was a reason why we dont see more covers on the road over the last 3 decades

[freebeard]

This should be adequate for brake cooling:

Originally Posted by mooneyesusa

MOON WHEEL DISCS can be made up to 46" in diameter. Don't see your size listed? Contact us for custom applications.

http://www.mooneyesusa.com/MOON-Disc-Screw-on-p/md11-sc.htm
Their order form pop-up lists 10-18".

That example shown with the open center probably clamps to the rim. I'll see if I can find the reference.

Edit: I came up dry on Ecomodder, but there's the very thing:

http://www.ryderfleetproducts.com/deflecktors-22582512410s/fuel-saving-wheel-cover-for-steel-wheels-22.5-p-dfl-22582512410s

It turn out they're made from (possibly vinyl-coated) fabric.

If your taking the Donner pass, it would be easy enough to remove them at the summit. Next time you're there, check out the restroom at the 'Safety Stop', it's the most awesome one I've ever seen.

[bikeprof]

Hmmm, big trucks loosing "their" brakes is not the trucks fault.
The operator behind the wheel is THE fault behind trucks "loosing" the brakes!

Been driving since 1977(large trucks), and have seen quite a few instances where trucks were in "runoff's" and that is a good feeling but at the same time, amount of dollars that someone had to pay for the extraction is/was what makes an impact to me...

1. Run off ramps ARE designed for the occasional reason of mechanical disparity
2. Run off ramps, there ALSO for the more often ERROR in driver/operator F__K UP, exits installed there hoping these will save lives(and they do!)
3. Brake pad/shoe mal-adjustment happens to be top three use of run off exits
4. SPEED, actually... OVERSPEED is also top three(hmmm, sure!?!?), hahahaha

But wheel covers, I would debate this.
More an excuse and blame to accuse others of driver error; UNLESS the wheel covers cover BOTH sides of wheel assembly(in n out), covering drum, not letting any air thru to cool stuff off. (these don't exist though...)

[cosmick]

Cover either single side of a household style freestanding box fan, and no air will flow through.
Likewise brakes, whether drum or disc, have splash shields blocking the inner side. So if the wheel isn't open, there's no cooling airflow.
Debate the idea all you like, but notice that even in Nascar, where there's virtually no braking, they still don't use discs over the wheel faces. It's been tried, the results looked good in the wind tunnel, but on track testing was what killed the idea. By the way, your aero efforts miss even the brake cooling ducts that Nascar still uses in some races. Those would add drag, and most people do them wrong at either end, or both ends.
Choose a flat face wheel like my S-10 in my Newb Intro thread titled Sad about good MPG. Those help MPG compared to dished wheels, but still help brake cooling.
All y'all's reasoning and book learning means nothing in reality, until you've tried it. Or someone else has. Part of what makes humans human is the ability to learn from the mistakes of others.
I understand liking trying things for yourself, but when other lives are at stake, do you really have any right?
My brake fade happened as safely as possible short of renting a closed venue.

[bentring]

What would be the difference, aerodynamically as well as the brake overheating issue, between moon covers and rims like these?

[user removed]

You honestly think they don't use brakes in NASCAR.

https://www.youtube.com/watch?v=IiF7l8hjKnE

regards
mech

[bikeprof]

Thanks for the VID, Old Mechanic!

As racer, mechanic and almost professional spectator(professional to some races :-) ), glowing brakes is a sign of proper set-up and proper usage of equipment as it should be...

Glowing brake rotors is a beauty that most spectators do not absorb as they do not see that because of the distant(distance) bleachers here in the USA. In other localities/countries, spectators "ARE on top" of the vehicles which is dangerous BUT VERY THRILLING :-))))

Rallying is a place where rotors that change color(s), like chameleons, can be found and that is something to observe!