In the past year, reports have come and gone about Volkswagen adding a TDI Clean Diesel option to the popular Tiguan compact SUV.

We have reported here at DieselDig recently in fact that the option was virtually a done deal to come as soon as the 2013 model year.

Instead we learn from the horse’s mouth this week that indeed Volkswagen will offer a diesel engine in the small SUV, but not until the 2015 model year.

The news is shocking as one has a hard time making sense of why. VW product planner John Ryan has said that the dealers are clamoring for it. He has said that customers are clamoring for the same diesel that gets some 27% better fuel economy than the turbocharged gas engine.

The holdback is two-fold say reports. One is price. Because the Tiguan is heavier, the same engine that powers the Jetta, Passat and the upcoming Beetle would pollute more than the others. This would require the more expensive urea injection system.

That alone has given Volkswagen product people the heebie-jeebies because they worry the additional cost would make the TDI Tiguan uncompetitive. The second issue is supply concerns for the home market where diesels make up a majority of sales.

Until Volkswagen can get the technology and supply issues lined up, we will have to wait.