can you use regular unleaded gas in a 2014 tiguan awd r line 4 motion

Unless the vehicle calls for premium gas, then yes it is true. Here is some info on regular vs premium gas... http://www.cartalk.com/content/premium-vs-regular-1

I would only recommend it if you are unable to get the higher octane fuel. This vehicle is designed to use the turbo much oif the time. This allows you to get the kind of performance from a 2 litre vehicle that you might expect from a 3 litre without a turbo. And with VW's dual mas flywheel, you get the same ride quality as a V6 from a straight 4. I recently rebuilt the top end of a 2.0T FSI that had clearly used lower grade fuel and it had more than the normal amount of carbon build up. Having said that, it is an easy fix that the VW dealer can take care of with a good intake cleaning during your routine maintenance visit. If you want turbo performance you have to buy the higher octane fuel. My preference is always for Diesel engines due to the better MPG. Nearly a third of all european vehicles are now diesel. They pay $10 a gallon - so they know about fuel economy !!