I got 3.7 in the DEP with 21s cruising at 70 from LA to AZ. Doable, but boring.I thought the small battery would be more efficient. But I reset my Trip A in the Touring and did 75mph from SJ to SF and could not pass 3.3miles per KWh (with heater on 70F in 50F ambient)
On the way back i drove a bit faster (between 75-80mph) and averaged 3.1 miles/KWh. But in both cases i didn't use any significant acceleration and mostly just cruised.
Either way, i don't see how people are getting even close to 4.