Our ISL370 CAPS was built in July of 2003. I run XPD in every tank, and add Amsoil Cetane if I will be doing extended mountain driving. I've read many of the pro/con on ULSD and to additive or not. My thinking is the engine was designed for pre ULSD fuels, and the costs of the additives is very small in the total scheme of RV'ing.
My DW has been a bit suspicious that I sometimes just make up problems so I can go spend some coin on my RV Toy:)! So, when we first bought our 04 Allure, I put together a small list of items to expect not 'if' but 'when' we'd have problems down the road. The ULSD impact to our era engine is on this list.
I also have done preventative maintenance on ULSD change over by having the fuel hose lines changed over to the Generator and Hydrohot with newer Gates hoses. IMO, that has a higher probability of impacting more RV'ers form the ULSD change over then engine damage. I also see it as a potential safety item, due to leaking fuel's can sometime ignite. I also wonder where is the safety related recalls on the damage of ULSD on hoses?? How many RV's are lost due to this problem?
I have no real problem with us humans becoming smarter and deciding changes are needed to stop problems. However IMO the CARB gang got way out of line and pushed many changes thru that were not well thought out - and really impacted the wallets of many people.
Be good, have fun, be safe,
Smitty