I just confirmed this morning that my Prius' minimum CC speed is 44 km/h (27.34 mph), not 40 km/h (25 mph) as I read somewhere in the Forum before. I actually set the CC at 50 km/h and kept lowering it untill it settled at 44 and lowered no more. I guess even the police won't charge me for driving @ 44 in a 40 km/h school zone? (Keeping my fingers crossed). Are there any reason you want to cruise control the Prius at even lower speeds, like what, 30 km/h (20mph)? At that kind of speed I find it better to use ECO mode to control the gas paddle.
I think the standard CC minimum is 25 MPH; the DRCC is listed as 30 MPH. But I can set mine down to 28 or so. No way to change it as far as I know.
I just had a brain cramp and wondered what DRCC means so I google it and found "Durham Rape Crisis Centre " oh my god what the heck does it have to do with the Prius' Dynamic Radar Cru....oh, so that's what it really mean
That would require Toyota's more advanced DRCC that works down to 0km/h (so yes you can do the entire bumper-to-bumper commute without touching the pedals...). Alas, it's saved for the higher end models (thus allowing Toyota to offer the basic PCS and DRCC to lower models).
I can't say LS460/LS600h's system does because I haven't tried it but Toyota does have it on the Crown (not sold in NA) so they do have the technology. I wouldn't be surprised if the LS' does have it (given that MB has stuffed their Distronic Plus system into the new S-Class... "plus" being the one able to go down to 0km/h). HS definitely not. It's still a premium feature.
