I agree it's going to take a hit with larger tires, My Supercharged FJ with 33"s and tons of gear on it can barely go over 200 miles when towing my off-road trailer, I think the Cyber truck will do a lot better and it doesn't drink 93 octane!
If i can get my hands on one she will be 150 miles a day of low grade clay roads with not much gravel, See how she goes!!! Im opting for the TRI motor because all the mud will reduce range big time i imagine. Im still debating this or a new JL Diesel. I really would like a CT to work for me though.
I have a Ford F-150 switched from stock tires 265/70R 17 to the same size in Toyo open country M/T 10ply/load E very aggressive deep tread. I lost 3 MPG, 22MPG to 19MPG at 70 MPH. A loss of 13.63 percent. The physics of rolling resistance, (see Mitchlen Tire "tools" Rolling resistance comparison). Increase tread depth, tire size, load rating, Load, all increase rolling resistance. Add my tools, 95 gal diesel fuel tank for tractors. Now at load capacity around 7500lbs. MPG is down to 15MPG at 70 MPH a 31.81% loss. I believe the Tesla pickup will be much efficient than the Ford F-150. These are the numbers I have to compare. Tires are Tires.
I would argue rolling resistance is a bigger part of Tesla's energy consumption, the aerodynamics of the body and aerodynamic improvements of drastically reduced cooling needs. So if making the same exact tire change on the Tesla I would expect a bigger efficiency sacrifice.
I would like believe that Cycberytrucks posted ranges are with aggressive offroad tires it was shown with. I have not seen these Goodyear tires before. I think Tesla asked different tire manufacturers to design a low rolling resistance offroad tire for the cycbertruck, Goodyear won. yes, you would increase efficiency if you switch to a low rolling resistance street tire. Use the reverse of my switch from Michelin 265/70R17 to Toyo MT 265/70R17. A lost 3 MPG, 22 MPG to 19MPG. If cycbertruck was range tested/projected on paper to have a 300-mile range and switched to a light truck street tire, you should/might see an increase of 13.6% - of range 40.8 to 340.8
I live in AL where people love to hunt and drive on their properties. Heck, there are guys that build hill climbers and rock crawlers and take them “exploring” every weekend. My point is that loads of people look for opportunities to get off-road in their well equipped vehicles. Most just “jack up” their truck and never take it off road . Status symbol. If you think about it Jeep has built and entire platform of vehicles on getting off the pavement.