The front are 6.5" and the rear are 5.25" and if yours has tweeters then those are .75"
Go to crutchfield.com and enter your vechicle information in the outfit my car section it will bring up the size for you
check out crutchfield.com. enter year and make and they show all specs for audio related.
18's are the biggest
R15 195/65
12,676km
6.5
6.5in
6.5" round speakers in the front and back.
6.5"-6 3/4" Speakers
6 3/4 inch or 6 1/2 most 6 1/2 will fit it is a very popular size.
15.7 gallons http://www.cargurus.com/Cars/Specs-t26207-2002-L-Series-4-Dr-L200-Sedan.html