Vlad - The main tank has around 12 gallons, the secondary tank maybe 2 gallons. They are pretty empty adn cruddy on the bottom. I am planning on doing an oil change ASAP. The Diesel tech also said run straight 40 in this as well. I got 4 gallons of 15w40 in it now when it was low just to get it onto the stick assuming it was going to be drained out anyway. It was a shame to waste $70 on oil to drive it 5 miles but better than wipping out bearings. Tonight is power washing day. Get all the grime, mold, and nasty greese off everything I can from the outside to the underside and chassis. This way I can find all the fittings so I can lube this mother up. Eventually, I will paint the frame but first I need to make sure it is mechanically sound, then work on the cosmetics. Just a good cleaning will do for now. Paul - Clark is an hour north of us. My BMW club has meetings up there at the Deutscher Club of Clark, NJ so I am a little familier. They also just had a car auction at the Armory in Westfield. Thats exit 135 off the Parkway. We're off exit 91. Give me a call at the shop 732-370-8800 if you want to swing by.