3. How often the tyres be rotated ?
Any good quality (name brand) oil doesn't need any additives. Additives are generally just another way to relieve you of some cash.
The only one that i have heard much about is the Lucas oil product, it adds to the oils ability to flow and adhere to the surfaces of the metal. Other than that regularly scheduled maintenance is the way to go to get the most out of your machines.
205 approximate width in MM 55 % sidewall height of the 205 R top speed 16 tire size in inches (wheel size) Soft tires (high performance) last between 20,000 - 60,000 miles. Harder tires (snow tires, touring tires) last between 30,000 - 80,000 miles. Tires should be rotated every 5,000 miles or at twice a year.
205 refers to width at the bead (205mms) 55 refers to side wall height (55% of bead width) R stands for radial 16 is the rim size in inches W is the speed rating (210 kilometers per hour) Average tyre life 40 to 50,000 kilometers You should rotate every 3 months.