Parts Covered for 8 years or 80,000 milesIf your vehicle has one of the following parts, thisFederal Emission Warranty covers that part for aperiod of 8 years or 80,000 miles, whichever occursfirst.These limits are counted from the time when yourBasic Warranty begins under 2.1(D).
Since, the upper leaf blade is directly faced to the sun, the rate of transpiration increases. Hence, to prevent excessive transpiration, stomata are more in lower surface i.e. relatively less transpiration happens from the lower epidermis. Plants also remove water in the form of (liquid), this is guttation.
Why does the lower epidermis of leaf contains more stomata than upper epidermis?   Because the top of the leaf is covered by the cuticle of the leaf which prevents water loss and transpiration.