Sunday, December 12, 2010

Pushing the Limit

The MINI-E speedometer and power gauge

During my eighteen months with MINI-E #250 I have tried to test the car in every way. I have pushed the range until I thought I would need to be towed, I have overloaded the cabin with hundreds of pounds of cargo, I have seen battery temperature extremes from 118 degrees to a low of 39 degrees and I've generally driven it like someone that is trying to find the weak links so BMW could identify them and improve upon the findings in future models. 

I have also not forgotten to test the 95mph electronically governed top speed either. In fact, on a few occasions I have tried to push it a little higher and beat the limiter. I did succeed to squeeze out 96mph, but not any more than that. I was really hoping to get a bit closer to 100, but after a few attempts I have all but given up. When you hit the 95 mph limit, the car cuts the power until it drops down to about 90 and then supplies power again, so you constantly bounce between 90 and 95 if you just keep the accelerator floored. I even tried to do it going downhill with the hopes that I could squeeze out a few more mph but it didn't happen. 

It's not that the car doesn't have the power, because it does. In fact, at high speed it has plenty of power and gets up to the 95mph limit with ease, but the electronic limit then takes over. I'm not sure if BMW just doesn't want us to have an accident at such high speeds or if perhaps the car just isn't geared to go faster and could have problems if we were to drive it to the limit. There is also the issue of battery use at these high speeds. The car uses a lot of power pushing the air out of the way at these high speeds. From my experiences I surmise that driving the car at 90+ mph continuously would cut the range in half of what the car would normally get so you wouldn't want to drive that fast often unless you were not far from your charger.

I think it's that reason that the other automakers that are coming out with pure electric cars in the near future have all set electric governed top speed limiters like the MINI-E has. For example the Nissan LEAF is limited to 90mph, the Smart Electric Drive can only go 60mph, the Mitsubishi i-MiEV is 81mph, the Honda Fit EV is 90mph and the Ford Focus EV is limited to 85. I'm pretty sure these cars, without the limiters could go much faster, but they would then use up the energy stored in their packs extremely fast and possibly leave their driver stranded and unable to make it to their nearest charge point. 

Personally I don't think there is much a need to go faster than 80mph in an EV (unless of course it's a Tesla Roadster!) so I don't mind the limiters as long as they are at least 80mph. In just about any driving situation, you wouldn't need to go faster than that to keep up with the flow of traffic on any highway. As long as the car has the instant torque and plenty of low speed power you would expect with an EV. The trade off you sacrifice in range just to drive a little faster just isn't worth it. I know I'm driving a little slower than I used to now that I'm driving an EV(except when I'm testing the top speed limit of course!) and when I think about it, I guess that a good thing.

1 comment:

  1. It's good to see you are having fun with the car whilst you are testing