Are you saying to go to 40 series on all four wheels, or just the fronts?
I had assumed that the OP was looking for wider fronts as well as the ability to do a four wheel rotation.
My 2005 GT roadster was OEM Bridgestone 225/45/18 front and 245/45/18 rear. Single directional no less. No ability to rotate, short of cross rotation which would requre remounts. This voids all tire manufacturer warranties I found out the hard way on replacement set of Michelins, which were non single directional.
It ate the OEM tires in about 20,000 miles. Not equally of course. Just ate down to bare threads on the inner front.
The second set of Michelins it ate in about 30,000 miles. Which is when I found out about the warranty issue.
Multiple alignments and shop opinions didn't seem to help. I ended up playing games with used, same manf, model, size tires off eBay for a while to run a set to where all four were equally worn and simultaneously replaced.
I considered going to cheaper tires and accepting that at 20,000 miles at least one would be dangerously unusable and just replace all four then. But I hate waste and, my life experience with tires has been that cheap tires always gave me headaches. So, I finally opted for another set of Michelins because COSTCO has such good deals on them. I drive the car much less now and have only put about 6,000 miles on them. I haven't measured tread depth in a while but plan to rotate them side-to-side when we get some nice weather.
Along the way to 90,000 miles I found this wierd thing with tire wear - this car & the Michelins - setting the fronts to 31 PSI cold and the rears to 36 PSI cold - gave me the longest tread life before some wierd wear pattern made at least on of them unusable. Go figure.
Don't even get me started on TPMS sensors and the $160 I wasted on a set of those because tire tech "swears" I didn't get the right ones, that mine are for a 370Z, even though part number is exact match to OEM replacement number. To be fair, my "OEM Nissan replacements" bought off eBay, might be some cheap Chinese knock offs. Although they look identicle to the originals and are stamped with the same part number, they do lack a couple of other markings that the OEMs have.
So, I'm stuck with the aftermarket sensors that COSTCO installed, which for some strange reason, only work when the outside air temperature is above 65 degrees or, if the car hasn't been started/driven in a coupld of days. Most of the time, I get only two or three readings.
The whole TPMS thing, especially the 4 wheel kind like our Zs have, turned out to be more headache than value. This was true across all makes and models which is why it was shortlived.