[JB3]

Originally Posted by 2007 ion2

fairing the rear wheels can lead to issues if the vehicle is driven in the winter, as snow and ice will build up. taller (and yes, they are wider) tires are heavier, and changes the drive ratio. this will likely lower your economy. my car starts out almost as aerodynamic as a prius, but a rear underpan is the only aerodynamic mod that in and of itself made a noticeable difference. everything else was a minor cumulative effect.

235 (width in mm) 75 (sidewall height as a percentage of the tread width) R (radial) 15 (rim diameter in inches).

this is a cool mod, looking forward to seeing the efficiency numbers with the more practical engine. American vehicles just aren't built as light and aerodynamic as the euro vans are. they also have a lot smaller tires and shorter gearing to keep rolling mass down and make more out of the power. bringing the aerodynamics up to snuff is a great next step given the small engine you have. filling body gaps with sticky foam weatherstripping, silling door handle recesses to the point where you can just get your hand under the handle, fairing windshield wipers (be careful, you'll still need to be able to get in there to clean snow out), cleaning up the front end, fairing chumky window frames with shaped sticky foam weatherstripping, and under pans will all yield better efficiency, and make your engine effectively more powerful. I'm a fan of coroplast, it's cheap, easy to work with, and looks decent.

im looking forward to underside aero mods id like to do. Right now im hamstrung by a stubborn clutch issue, but once I get the thing nailed down, I can start flattening out the mountain range I have going on down there