jeffand wrote:The only reason a Tesla can go so fast is because its battery is more than 3 times the size of the Focus battery.
I'm thinking that another reason is that the Tesla has a motor that is three times as powerful as the FFE motor. If it had the same or similar motor as the FFE, it would probably be programmed with a lower top speed, closer to the FFE... Perhaps its top speed would be even lower than the FFE, since the Model S is even more of a pig than the FFE - almost 5000 pounds!
In my opinion, the absurdly low limit on the FFE's top speed is probably very conservative - I'm guessing that the drive system is capable of more, at least 100mph. Here's why:
1) The Leaf, with a programmed max of 92-93 mph, has a similarly-sized battery (24kWh) and similarly-capable motor (Leaf is 80kW, FFE is 100kW... the Tesla, 310 kW!) This is about 8mph more than the FFE, and the Leaf doesn't even have a thermal management system for its battery. So I'm guessing that the FFE, with its thermal management, should be able to overcome any heat issues at a sustained speed of 93mph or higher.
2) The Volt has a top speed of 101mph, and there's a youtube of a guy doing it in Needles, CA in pure electric mode. The Volt also has a similarly capable motor (111kW), but has a much smaller, thermally managed 16kWh battery. I would think based on jeffand's theory of bigger battery means higher top speed, that the FFE should then be capable of over 101mph if not for its annoying speed limiter.
So maybe that low limit might be related more to what paw160 mentioned - that perhaps the way the FFE is geared, at 85mph the motor is near where the torque really starts dropping off. But then I've hit that 85mph numerous times just to merge into the HOV lane, and it sure doesn't feel like the torque is ready to drop off... the FFE pulls and pulls right up to its limit.
Wish there was more info out there. Without published documentation from the manufacturer it's all just conjecture by a bunch of hacks like me.