- What is the biggest tire size I can get on the stock 18’s?
Gaustin70 on this forum has installed 225/65r18 tires on their stock height phev and claim it doesnt rub under normal city driving. They're a nominal 29.5" tall tire vs the factory 27.75", so they should have gained 0.9" of ground clearance from the larger diameter tire. But in reality it will be less due to the taller sidewall being more flexible than the shorter one but they still probably gained at least 3/4" of an inch.
- Will a BIGGER tire size give it a little lift or none at all? I need that extra couple inches for the back roads this coming spring/summer.
You will gain a little extra clearance, at most half of the difference in overall diameter, you will NOT be getting a "couple of inches" of clearance from tires alone however. To get that much you'd have to be installing 32's or larger and those aren't going to fit without extensive cutting of the wheel arches along with a suspension lift.
- looking to get off road tires put on the stock, even open to getting both off-road wheel and tire.. any suggestions?
If you really want the offroad tires then I'd recommend going with a smaller diameter wheel (16's or 17's) and getting the tires on those. You'll have a far greater selection, and the tires will be much cheaper.
I personally am running 225/75r16 Cooper Discoverer AT3 4S's using 2016 Mitsubishi Lancer wheels I bought off Facebook marketplace. Zero rub at full lock on street driving and I'm even using a 3/4" wheel spacer to push the wheels out further, they do get very close to the plastic fender liner however. Even though these are a 29.25" nominal diameter tire, once they're under the weight of the phev they do lose a lot of their extra height. I am still at stock height as I am still waiting for my suspension lift to arrive.
Larger diameter tires will affect your speedometer and odometer too so you will need to bear that in mind as well.
You do not have the required permissions to view the files attached to this post.