Maxim tire sizes on the vehicle?

[Lancer]

I have a 205x78x15 in the trunk and 215x78x15's on the car.   I understand why the small one in the trunk.  That said, I would like to see something a little wider on the ground.  Some place I read something about tire/fender interference problems but I can't find it now.  Does anyone have experience, good or bad, with tire sizes? 

[Gunslinger]

When the Avanti was designed skinny tires were the norm and clearance for wider tires...especially the front...wasn't a consideration.  On my '70 I have P215/70R15 tires with no clearance problems.  The car has 15"x6" Magnum 500 rims.  A lot depends on whether you're using standard offset rims...too wide a rim and you can have some clearance issues...particularly the front.  

The spare tire well was never updated for wider tires and rims, which resulted in many cars not being able to have the cover fit flush with the trunk floor.  I've seen some modern 6.70-15 tires not fit in the well properly, even with original spec rims.  I use a space saver spare which allows extra storage plus the cover fits flush.