Builder said:I use Howes, too. Ask your local big truck parts counter what they recommend.
Just switched to Howes also. Powerservice is junk. Had a full compliment in my Duramax and it gelled two weekends ago. Was around zero. Tried the Howes as I heard it worked good and no problems to -10ー so far. Another fellow on another board had Polarpower and it did the same as the PS