Yes, the heavier weight oil will raise the pressure that much. No, it's not really a problem. My Explorer started losing a little pressure at idle when it got to about 100,000 miles, so I changed from 10W30 to 15W40 diesel-rated oil. Since I buy it 5 gallons at a time for my farm tractor, it's more convenient to run all our vehicles on the same oil anyway. Engines that run 5W30 oil when new will develop enough wear in 100,000 miles or more to use the heavier oil effectively, but don't do it on a new engine with tight clearances.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!