Dear Motor-Talk Community, I have changed spark plugs for three cars in the family, all three cars have now NGK spark plugs with flat seat and sealing ring. On the NGK website I have just read that it is recommended to put on spark plugs with 25nm – 30nm. I have set 20nm on the torque wrench for all 3 cars. Should I correct the torque again or can nothing happen because of 5nm difference? Next time I should go to the manufacturer’s site to Sufficient to lead Best regards Jan