Quote:
Originally Posted by euromodder
Sure, but when the battery is full, you're done regenerating, done gaining back the (extra) energy you pumped in going uphill.
Regen might regain 80% of the kinetic energy, that's not a lot compared to the potential energy it can get stored in it due to the increased height.
But that penalty is entirely caused uphill.
If without the trailer you're not using fuel going downhill, and your speed is kept in check by the aerodynamic and/or engine drag, then there's simply nothing to gain by adding the trailer - regardless of its weight.
You simply can't improve upon infinite mpg - unless you add regen 
Lightweight regeneration, that is, or you'll need to work off another weight penalty.
The trailer penalty will be less as it gets lighter, but without regen and short of a "design-downhill" matched to suit your streamlined combo, I'm rather confident the penalty will always be there in the mountains.
It'll get less as you shed weight, but it'll never go away completely.
So you might reconsider the time and expense you want to spend on it.
Or get a vehicle with regen, and streamline that ... |
*It is the PhDs at the national research lab which published the downhill penalty,which existed anytime braking was involved.
*The point I'm attempting to illustrate is that when in mountain driving during road tests,the mpg is affected by not only the additional mass going uphill,but also on the descent if it causes braking which does not exist without the trailer,with kinetic energy lost to heat.
*It makes it very difficult for accounting purposes.
*A good reason why SAE says to stick to level roads when testing (not an option for me).
*AC Propulsion's 'Long Ranger' range-extender trailer weighs only about 180-pounds without its engine/generator vs 620-lbs for Viking.
*Viking is longer than necessary for a boat tail.
*A shorter proper tailed trailer with resin-coated papier mache or pre-preg carbon fiber full body would be of insignificant weight liability.
*Long Ranger has radials as well and AC Propulsion reported a 2% mpg benefit which Viking doesn't enjoy.
*If Viking weren't so long she'd fit inside the A2 Wind Tunnel and I could just have the drag measured directly.
*The T-100 debaucle has pretty much scotched any plans for A2 come fall,Bonneville as well.
*Perhaps by spring of 2014 I could be in a position to mock up a modular 'proper' tail/trailer configuration with faux wheel(s) and get it to A2 for a series of measurements of tails and trailer both.