Just a few of the many letters sent to GCF, Inc.
“It’s been several years since I wrote to you to thank you for your
wonderful oil filter and its time and money saving for us. The same
filter is still in use and we’re still more than satisfied with its
Four years ago Jim decided to replace his 1693TA Caterpillar engine with a 400+
Cummins. The 1693TA was still in action but he wanted to cut down on weight to
get better payloads. (He’s made several innovations on his 1973 Peterbilt to
Anyway, when the mechanic took out the 1693TA he could not believe the way the
parts looked. They were clean and the oil was beautiful. He all but called Jim a
liar when he told the mechanic he didn’t change oil anymore. He explained the
principle behind the filter and told him he’d been using it since 1984.
Jim changes the filter about every 10,000 miles and adds only 3 ˝ gal. of oil
at that time. He changes that often because he has been a grain hauler for 8 or
9 years now and he is afraid the excess dust, etc., might be a little rougher on
it than when he was pulling his reefer when he first put on the filter.
Thanks again, for the best bargain we’ve found since Jim’s been in the
trucking business – about 40 years.”
(for) Jim Cooper
“From all the letters we have received over the years,
this one, from a trucker’s wife, is my favorite!” -