I used the Delvac 1 0w40 ESP in my 95 Toyota diesel and I did not notice any improvement in cold starts over the 5W40s that I have been using for winters. It seemed to work well but after 4000 miles it really started to burn the 0W40. I topped it off with T6 5W40 to last till the 5000 mile mark and once the T6 was added the motor stopped its burning of oil and seemed to run a little quieter. Now the quieter probably is just me but the burning of oil isn't. It was cheap though at $6.25/L pretty much the same as the T6. Well the T6 was $1 less for 4L.