A FLEET WE DO WORK FOR HAS A 99 CHEV TOPKICK FOR A BULK LP DELIVERY TRUCK, THE MOTOR IS A 454 RUNNING OFF OF LP, THE MOTOR CONSUMED OIL FROM THE START AND GOT WORSE WITH MORE MILES, THERE ARE 20,000 MILES ON THE MOTOR AND IT USES A QUART OF OIL PER 500 MILES, ... Login to read more.