Rubber was mostly replaced around 94 , the limit for b20 is still a lot of rumors .
Or maybe a number of reasons , from being around the bio-diesel for a while , an indication I have been hearing is that the newer common rail [ High pressure systems ] are polymerizing [ making stringy goo = technical term ] , that may be a biggy .
I for got my 1st thought when seeing the lead post , Northern Tool , some stuff the price is OK , but everything that is related to alternative , like solar , bio , seems like they are just making look bad with over pricing , they usually have the low grade solar panels , & sell higher than the good one [ I've been looking / using for $2. 80 - $4. 25 per watt for some time , seeing Northern Tools sell for $9. ++ per watt & higher ] .
Point being look around a lot before buying .