You have a tire out of balance, a bent wheel, or possibly loose lug nuts. One of the tires may also have a broken belt.
Perhaps tires need balancing
get your wheels balanced
30mph
starts out about 17mpg but will increase to around 20mg driving at 60mph with mileage
that could be a number of reasons... first i would recommend getting octane booster because it sounds like bad gas to be honest!
bad fuel, shorted mass air sensor, if the car is automatic might be low transmission oil
60MPH is faster than 80kph 60MPH = 96.56064 kph 80kph = 49.7097 MPH
Possible causes for a shake include a bad tire, bent rim, loose lug nuts, or an out of balance tire and wheel.
No, a 60 mph zone means you must drive at a safe speed for the prevailing road conditions and not exceed 60mph.
60-35=25 25/5=5 5 mph squared
sound like a bad universal joint, vibration more noticable under load?
One mile at 60mph would take just one minute.