Wheel sizes

Hi, 2 questions - I have a 1994 manual Land Rover 200TDi.

First - I have been given some wheels that have a different wall size to the ones fitted. I have 205x70 on 16" fitted and want to fit 225x80 on 16" wheels. I know the width (225) will possibly decrease fuel efficiency but will the wall size matter? I was going to fit to the rear axle.
(Question you ask - why am I doing this = Answer - they were free and have 10mm + tread!)

Second - the front hub was dry on the outside when I got the car, I have drained the oil out (not a great deal) and refilled it, it now leaks - should I worry or just keep topping it up (2 or 3 drips after a 50mile journey is typical)

Any help would be appreciated

First question - You can't fit different size tyres front and back, all 4 need to be the same rolling diameter, in effect sidewall height needs to be the same front & back, width doesn't matter.

Second question - I assume you mean the swivels are leaking slightly, cheapest quickest fix is to let the oil out and fill with one shot grease instead.

so youve learned the 1st rule of lr ownership

if it aint leaking or broke dont fookin touch it leave well alone