I know, I've questioned it and questioned it several times, been on-going for months with this usage. I checked it myself at home, no leaks or smoke. I took it to Abbey Motorsport, they also checked it over, no leaks or smoke. I called Mike and he was puzzled and said to try monitoring it with different types of driving, so quite heavy footed for a week then just on cruise for a week for example... same usage. Then he advised to try changing from 5w-40 to 10w-60 as the thicker grade may reduce the usage, or so he thought... still the same. Took it back to TD for investigation and it ended up being there 4 months before I got it back (previously been there 2 times, for 6 months each... first time for engine rebuild / turbo etc and second time for a misfire). Minimal testing was done during this period to my frustration but Mike couldn't find anything wrong with it. Mike fitted an oil restrictor to it but still using the same amount of oil... still getting no smoke, no leaks... and performance remains normal, so I'm baffled by it too!