6.5 TD fuel filter? | Chevy and GMC Duramax Diesel Forum 6 Diesel Forum. 6.5 TD fuel filter? Jump to Latest Follow 1 - 6 of 6 Posts. R. russellw · Registered. Joined Oct 18, 2010 · 4 Posts . Discussion Starter • #1 • Oct 26, 2010. I just Leroy Diesel | 6.5 Diesel Products #5 Upgrade to a free flowing exhaust system. This will help turbo be more efficient and raise MPGs. #6 Upgrade you Air Filter System. The S&B is a great system. On 97-2000 trucks and Suburbans they have a good system know as a K47. You just need a free flowing element for those witch are also in the Air Filter System link above.