Tire sizes?

The first number in tire size is the tread width in millimeters. So, you are only going 10 mm wider and that is 5mm on each side.
That should work out fine.
The most important thing is to not change the circumference of the tire. If you do this; it will affect gearing, the speedometer, speed sensor and speed related elctronics like speed sensitive steering and it goes on and on. Getting tires that are a lot bigger does not always help the performance aspects of a car. If you are trying to get straight line traction, you can do things to the suspension or get soft tires. If you change the suspension so it works well for straight line and get soft tires, your performance going around turns will suffer. So, in that aspect it is give and take and stock is usually the best blend of the performance the car is capable of. Getting huge tires will slow down acceleration tremendously. Rotating 5 pounfs on a wheel is like carrying 30 pounds in the car. Or more depending on how big the tires are. Brakeing will suffer for this same reason.
I looked up the tires you have selected at the tirerack and they are both excellent coices.
If you are looking for performace to improve around turns, don't change the ride height, but do get good, high quality struts and/or shocks. Changing the ride height will affect the balance of the car. I lowered a car with standard lowering springs long ago before I learned my lesson. The springs dropped the front of the car.5" more than the rear. Does not sound like a lot but it put more weight on the front and it handled terribly. The front end would plow through turns. It constantly damaged the exhaust and I finally switched it back to stock. It handled better than ever and a pait of BF Goodrich Pilot Sports and TEIN struts and shocks at stock height settings. Made the car handle like a dream.
All I am saying is just don't stray too far from stock dimensions. Engineers spend a lot of time coming up with the designs the cars come with and it takes a lot of work and giving up some comforts before you can even get a little more performance out of them.
Let me know if you have any more questions.

IMMA JEEP CJ KINDA FELLER

I HAVE LEARNED OVER THE YEARS THAT A WIDE "PERTTY" IRE ON WIDE RIMS MAY BE JUST THE TICKET WHEN RIDING IN THE BEACH OR IN SANDY CONDITIONS----NOT WORTH A DARN IN MUD, WHERE YOU WANNA SINK DOWN TO THE HARD STUFF, SO YOU CAN GET TRACTION

NOT ONLY THAT---I LEARNED THAT THE PERTTY WIDE TIRE HAS MORE CONTACT WITH THE ROAD. MIGHT BE GREAT IF YOU ARE DOIN' 110 MPH AROUND A CORNER, AND WANT "GRIP" NOT "SLIP AND SLIDE"

WHICH SORTA LEADS ME UP TO----MORE TIRE SURFACE (TREAD) CONTACTING THE ROAD----MORE FRICTION---LESSER MILES PER GALLON

YOU MAY NOT THINK A LITTLE COULD MAKE A DIFFERENCE----BUT IT WILL---HOW MUCH? I DO NOT HAVE A CLUE.

I WAS GONNA INSTALL SCREEN WIRE ON A FRAME, THEN SLIDE IT BEHIND MY GRILL TO KEEP THE (WHAT WE CALL) "DUMB BUGS" (HARD SHELLED BEETLES THAT FLY AROUND AND BASH INTO ANYTHING) FROM BATTERING MY RADIATOR FINS SO TERRIBLY

IMMEDIATELY I NOTICED I WAS RUNNING HOTTER--BUT NOT OVERHEATING. REGARDLESS, I DIDN'T LIKE IT

MY POINT. EVEN THOUGH IT LOOKED OK. AND YOU "MIKE" (PRECISELY MEASURE) A SCREEN WIRE STRAND, THEN COUNT THE NUMBER OF STRANDS IN A GIVEN AREA (I DID A 3 IN. X 3 IN.--I DON'T MATTER!)----AFTER YOU DO THE MATH---YOU HAVE LOST RIGHT A 1/4 OF YOUR OPEN SPACE, OR AIRFLOW THROUGH THE SCREEN. SO MY TAKE ON THIS DEAL IS, "DON'T LOOK LIKE MUCH, BUT IT REALLY MAY BE!"

I HAVE DROPPED DOWN FROM THE "COOL" WIDER TIRES---DOWN TO 235-75-R15s (COULD STILL GO NARROWER, BUT THEN PRICE STARTS GOING UP, TO ME THIS IS MY "HAPPY MEDIUM").I'M SURE TREAD DESIGN/ ROAD CONTACT FACTORS IN TOO, AS FAR AS MPG. YOUR INTENTIONS/ USE OF THE TIRE WILL MAKE YOU CHOOSE THE TREAD. I WANTED GOOD HIGHWAY USE, BUT DECENT TRACTION OFF-ROAD, WHEN I NEED IT.I'M NOT AN EXTREME OFF-ROADER (LIKE I USED TO BE) I NOW ENTER A QUESTIONABLE SITUATION WITH A WELL THOUGHT OUT PLAN--I USED TO JUST "GO FOR IT"!

JUST SOME THOUGHTS

THE MEDIC

I have spent many years in the tire business and I do not advise changing the size like that. Although the width measurement is the one that appears to change, it will also change the circumference of the tire because the sidewall height is a ratio percentage of the width. Changing the circumference will effect many things such as the ABS system, the shift points, the speedometer, fuel mileage and engine torque. Use the proper size tire.