Normal tire pressure loss?
 

People say that one should check tire pressure monthly. This implies that some loss of pressure in the tires is normal.

I got this digital tire pressure gauge from Walmart ("AccuGauge") and a cheapo tire pump.

Measured tire pressure on a 70-degree morning about 32 days ago. Front wheels read 27psi, rear wheels read 26psi. Reinflated the tires to read 32.5psi according to the gauge.

Measured tire pressure this morning. Fronts were 26, rears were 31. Reinflated all to 32.5 again.

This is approximately 3800 miles later (averaging 115/miles a day). Is it normal to lose so much tire pressure over ~4k miles, or is my gauge f'd?

About 30% is city driving. I take corners hard, do about 1.5-2x times the advisory speed on on/off-ramps. I accelerate faster than normal. Does the driving style affect pressure loss or the distribution of such loss between front and rear wheels?

Thanks, and sorry for the n00b questions!

I'm gonna monitor tire pressure weekly now, see what happens...