Should i maintain tire pressure recommended by buick or goodyear? The tires are new and not the same manufacturer as the originals.
My car has 73000 miles.
My car has an automatic transmission.
Tire pressures imprinted on the sidewall of tires indicate the MAXIMUM PRESSURE RATING. Meaning, the maximum air pressure that tire is rated for. The tire pressures listed specifically by Buick for your vehicle is their recommendations for ride comfort which is 30 psi for front and rear.
Depending on the condition of the roads near you, running a few more psi than 30 will not really cause any adverse effects to your tires. I would not exceed 35 psi. The tire pressure label on some vehicles lists different pressure settings. Base line settings and "high speed" or "full cargo" ratings. Running tire pressures in between the two should be fine.