Metro aerodynamics

[SVOboy]

He's already getting low 80s on his test track. Mehbe he'll just never leave it,

[The Toecutter]

Yeah, low 80s in imperial mpg.

He still needs a front air dam, lowered ride height, side skirts, shaved door handles, rear diffuser, tapered roof spiler, the list goes on...

The impact of all aero mods on highway mpg would be about 40-50% for most cars, but about 5-10% for city mpg.

After that, it's time for weight reduction, and a fuel efficient but powerful diesel. Say, a 112 hp Opel 1.3 CDTI common-rail turbo-diesel. You'd get 90+ mpg with that and aero mods, and 0-60 mph in 7 seconds... Wouldn't that be a real sleeper? And you'd be able to run it on B100...

[SVOboy]

No, low 80s in us mpg. He was at like 99.x in IMP because he said, oh so close to the goal.

[The Toecutter]

Wow!

He should be shooting for 100s then...


But on his site, his record run is just over 60 U.S. mpg, unless he needs to update.

[SVOboy]

I'm going by what he's done in his 7.3 mile test loops in the daily report thread. Today he got 81.x us I believe.

[MetroMPG]

Originally Posted by The Toecutter

the list goes on...

.... and on... no kidding.

the test loop avg speed is 20 mph, so aero mods have a limited impact there, and the route is pretty optimized (couple of great hills). my main goal is to raise my hwy avg, and aero is the way to go for that.

[kickflipjr]

That boat tail should turn a few heads.

80mpg is crazy. What if you had a tank that was that high. I would of thought it was impossible before i started reading up on fuel economy. Now 40mpg in a hummer wouldn't surprise me.

[MetroMPG]

i cleaned off the old duct tape & cardboard grille block. i have an idea how to do it nicely (have one more krazy karpet left to cut up).

also, i traced the outline of my front wheel well onto newspaper... i see removable highway-only front wheel skirts in my future.

[krousdb]

Originally Posted by MetroMPG

also, i traced the outline of my front wheel well onto newspaper... i see removable highway-only front wheel skirts in my future.

I was actually thinking about fromt covers that were held in place with rubberbands that would allow the wheels to push them out when needed. On the inside of the covers would be a small roller on each side for the tire to push against. But that would be way too funky looking. I think I will stick to things that people won't notice. Heck, I average about 30 MPH so aero mods really won't buy me much.

Can you do A-B-A teesting with and without the wheel covers again? I would like to see that repeated with all four wheels covered.

[MetroMPG]

rubber bands, or a sheet of teflon plastic on the back of the skirt where the tire would contact.

i'll add "wheel skirts: all or nothing" to the things-to-test list. (i'm going to have to quit my work and go into testing full-time.)

i was wondering if there would be some complimentary dynamic in covering all 4 wheels vs. just the rears or just the fronts. e.g. the rears improved FE approx 2.8% at 95 km/h. maybe the fronts will be similar on their own. but maybe the net effect of front + rear skirts will be greater (or less) than simply summing their individual effects.