Wheel spacers

I know it's been covered a few times, but I've put 20mm on the rear and thinking of running 15mm on the front. From what I understand it should be half of what the back is on the front making it obviously 10mm, but will 15's make it understeer loads?

I can machine them down in the lathe if need be, curious to how much it will effect the handling.

I think from what i read ideally it should be 10mm wider at the back than the front but dont think its totally crucial if its 5mm more it should still help with understeer .... how come your spacing out the front anyway ? ..... backs i think always look like the wheel is further in the arch compared to the front ....

because ive got 15mm spacers i quite like seeing tyres closer to the arch. Can always take them off if handling pants.

Actually went up the road in her on friday only 50m or so, first time in 4 years.

Mine is 10mm. R u using hub centric spacers mate?

Yeah hubcentric, 57.1 CB but I'm machining then out to 59.1 for the R, and got aluminium spigot rings to suit after market wheels.

Will see what 15mm look like first if not take 5mm off them