After doing some research I decided to try reducing my monitors refresh rate from 60hz to 30hz and limiting FPS in the Nvidia control panel (program settings) to 30fps. I thought this may eliminate some stuttering.

However, I now seem to get screen 'tearing' where the image looks as if it has a line through the middle when I'm panning around the cockpit or the aircraft etc.

Can anyone help?

Thanks

Turn on Vsynch.

10 minutes ago, Bert Pieke said:

Turn on Vsynch.

In the control panel or in P3D?

9 minutes ago, BWBriscoe said:

In the control panel or in P3D?

Either will do it, as long as the control panel uses the application setting.

Probably easier to turn it on in both..

Monitor set to 30hz
Nvidia max FPS - OFF
Nvidia Vertical sync - use application setting
P3D frame rates - set to 30
Vsync - ON 

If I just set monitor to 30hz and don't cap frames, I get 25fps (at Aerosoft EGLL). If I then put frame rates to 30, it drops down to around 17?!

You limited frames to 30, but you were only getting 25 originally. My experience has been that if you limit the frames in P3D to a number that is higher than your system can actually produce, it tanks your FPS even further. Turning on frame limiting always costs FPS because it adds an overhead at the P3D level; if you have plenty of headroom, you can afford that overhead and still benefit from the sim having more CPU time for other tasks, but if you were already CPU-limited then it's not going to help. That's in my experience. 

You might try keeping your monitor at 60Hz and go into the NVidia settings and set the vsync to 'Half Refresh Rate'. That'll effectively limit the output to 30 FPS as the GPU will drop frames above that limit and so you should get a steadier FPS without turning on P3D frame limits, and less tearing overall. Worth a try, maybe.