New Shoes

Now that I've done exactly what I knew would eventually happen (falling-off the blog wagon) - Zippy demanded an update. He did this by finally chewing almost all the way through the Bridgestone Ecopias that came with the car at the time of purchase - 12,532 miles... abysmal tire lifetime by most standards. We do drive Zippy on a mountain gravel road about 3 miles per day - and log about 15 miles per day on a winding, paved mtn road... but honestly. The tires were literally bald - dangerous to drive with some careful attention. We were planning to install new tires but were trying to wait-out the inevitable snow so that we could transition straight to snow tires. The final straw was last week when Zippy could barely creep up our gravel road in the rain because the road was slightly slick - and the tires had no traction.

I found this blog post by Chuck Vossler quite helpful. We went with the Blizzaks mostly due to the fact that Zippy get about 20 highway miles per day and we wanted the additional durability of the Bridgestone tire. 

Next - I need to fine where to get these show chains. I've talked to our local BMW dealer and searched all over the web - to no avail.

Top End Consumption

When we began the drive down the mtn today we noticed that we had forgotten to plug-in Zippy overnight - so the battery was at about 75%. This is likely what allowed us to hit 99.9 mi/kWh on the consumption dashboard in the car as we exited the steepest part of the decent... and we still had 4 miles of gentle downhill to go. I suspect that the car charges differently depending on the battery level.

• Distance: 21 miles
• Duration: 39 minutes
• Average Speed: 33.2 mph
• Consumption (mi/kWh): 9
• Temps: 65

Whoa!

A great drive down the mtn today - and a new consumption record at the bottom of the descent of 86.3 mi/kWh... the car only goes to 99.9 and I don't think we will ever hit that. Perhaps this is the top-end.

• Distance: 21 miles
• Duration: 43 minutes
• Average Speed: 31.5 mph
• Consumption (mi/kWh): 8.4
• Temps: 65

Back and Forth

Quick update with the full stats from Monday - including the previous morning post. Had a short midday charge at Chautauqua while climbing. 

• Distance: 70 miles
• Duration: 2 hrs 31 minutes
• Average Speed: 28.8 mph
• Consumption (mi/kWh): 4.9
• Temps: 60-90

Morning Commute in Ideal Temps

Just the standard drive to work this morning - but the temperatures, as previously mentioned, really seem to positively impact consumption - even better than Friday

• Distance: 21 miles
• Duration: 39 minutes
• Average Speed: 32.9 mph
• Consumption (mi/kWh): 8.3
• Temps: 60-65

Weekend Driving

First and foremost - new consumption record on Saturday morning 53.5 mi/kWh coming following the same route down the mtn that we do for work each day. It was in the low 70s.

Sunday we took Zippy up and down the mtn twice, all around Boulder and drove four people to Lyons for dinner - highway driving over rolling hills and windy roads. We did charge the car at home for about 2 hours mid-afternoon.

• Distance: 79 miles
• Duration: 2 hrs 56 min.
• Average Speed: 27.8 mph
• Consumption (mi/kWh): 4.5
• Temps: 75-90

Ideal Temps?

I've read a fair number of accounts about the ideal temperature for EV operation and specifically the i3... I'm not an engineer like most of the folks who offer thoughts on this topic but my general impression is that there are a lot of factors.

For Zippy and the conditions under which we drive him, the mid-60s seems to be very ideal. As we reached the end of the long descent on our "to work" commute today, we had a new consumption record - 40.6 mi/kWh!

And the overall consumption by the time I reached work was 7.8 mi/kWh - well above the uppers 5s that I saw in the spring.

• Distance: 21 miles
• Duration: 44 minutes
• Average Speed: 30.1 mph
• Consumption (mi/kWh): 7.8
• Temps: 60-72