Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.
i dare ti doubt that you should use 205 50 r15. I think it's rather 205/55 r15 or 205/50 r 16.
The 65 r15s might rub on full lock or full Suspension compression
65s would be 2.4 inches taller than the 50s(23.1in). Is the wheel well in a GL the same as a turbo? Because a turbo has 205/55R16 tires that are 24.9 inches, that would make the 65s only 0.6in bigger than tires that barely fit. Might be worth a try, but I would bet they would rub. On my turbo driver side rear, I measured 28 1/2 inches horizontally right across the hub. Of course your speedometer will be off by quite a bit, maybe 7 mph or so. 65s would also give you a squishier ride.