Indy to Effingham in a 60?

I wouldn't think that would be an issue. Start the trip off in right lane at 65mph and have an RV park as backup maybe. Use Nav with trip prediction too.

EVtripplaner.com says it will take 153 range miles at 72F so, unless you drive very aggressively, or the weather is very poor-( cold and/or windy) you should be ok even in a 60 if you are going from the Indy Supercharger to the Effingham Supercharger. Keep in mind that you should try to make sure your charge is full when you start and as dsm363 says, start out the trip driving under the speed limit. Also, having just come through there last week, there are plenty of places in Illinois where the speed limit is reduced due to road construction so that will help. Good luck.

I thought plugshare would show charging in Terre Haute, but Terre Haute and the entire route is a charging wasteland.

However RVparking.com shows several 50A locations, including next to I-70 in Terre Haute and Casey, IL. I would call ahead to see if they would allow you to charge, some RV parks can be full, or just have inconsiderate owners. You shouldn't need it, but it is always good to have a plan B.

GSP