Comparing electrics is basically down to comparing MSRP and various incentives if applicable.

If you use city/highway range, the Empulse gets 77 miles from 9.3 kWh nominal battery capacity (142 Wh/mile @ 85% charge efficiency) and the Zero S ZF8.5 gets 70 miles from (probably) 7.6 kWh nominal battery capacity (127 Wh/mile @ 85% charge efficiency).

At $0.115/kWh, this represents a cost of $0.0163/mile Empulse and $0.0146/mile Zero.

The $0.0017/mile charging difference adds up to $170 over 100k miles. Pretty negligible in the grand scheme of things.

I think the Zero S ZF8.5 and the Empulse non-R are the most comparable of the two bikes. The ZF11.4 offers (in theory) significantly higher range than the Empulse (21% higher mixed, 25% higher highway) and the Empulse R is much better at being a sportbike.

IET and appearance IMO are subjective. The Empulse's IET should give it a small advantage in acceleration and top speed .. the bigger advantage would be if you specifically wanted the ability to shift gears. Riding both may be a good plan if you're on the fence.

Empulse non-R pros:

* faster AC charging (22 combined miles/hour vs 8.8 miles/hour Zero)

* 5-20% more range than ZF8.5

* probably more consistent performance, range due to liquid-cooled motor and battery cell heaters

* larger motor controller

* nicer brakes & suspension, sportier tires

* chain drive is more durable

Zero S ZF8.5 and ZF11.4 pros:

* ~10% more efficient, per range specification

* belt drive is very quiet, maintenance-free

* smartphone integration

* integrated storage (tank, charging cord)

Zero S ZF8.5 pros (vs Empulse non-R):

* faster DC charging (67 combined miles/hour), with optional CHAdeMO upgrade ($$)

* much lighter (350 pounds vs 470 pounds)

* $3000 lower MSRP

Zero S ZF11.4 pros (vs Empulse non-R):

* faster DC charging (88 combined miles/hour), with optional CHAdeMO upgrade ($$)

* 13-25% more range than Empulse

* lighter (382 pounds vs 470 pounds)

* $1000 lower MSRP

Edit: added a Zero S ZF11.4 comparison