i have an 83 300d and an 85 300d. the 85 has 220k and the 83 has only 80k. the 85 runs really well with the wvo but the 83 will only run well with it when the weather warms--the difference is remarkable. im in ca so its never all that cold for very long, but on the same morning i can fill these cars up, they will both start easily, but the 85 charges uphill on the freeway and the 83 will jerk and buck. i have changed many filters on both but never the filter which is in the gas tank on either. once this last winter when the temp was about 30 the 83 just would not ever turn over and i had to have it towed to the mechanic who got it cleared out and ever since then ive made sure to never have too much wvo in the tank. has anyone out there any idea why the 85 takes the wvo all the time and the 83 only when its warmer?? thanks for any feedback