ORIGINAL: GEORGY
How do you ''read'' the plug? Dark colour is rich? & light colour is lean? What is ideal? Will running at high altitude affect the colour? We race at 1700m (5600 ft) above sea level here in Johannesburg, South Africa.
George
Yes plugs operating temputure and mixture effecting carbons color upon plug will be the same at higher altitude also.
* Just keep in mind for good plug reading to be consistent engine operating temperature needs to be up into the 150/170 degree range.