I had been able to start my '75 300D without a heater down at 20 below zero before.

Sometimes my current 300SD will not glow. Something with the relay I suppose, but I have been able to start it without glowplugs at all many times. I'm not sure what the lowest temp I've started it has been, but I'd guess in the 40's.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)