There are a couple of issues with changing wheels sizes, but it’s a question a lot of people ask. That’s because the trend towards larger-diameter, super-low profile tyres doesn’t make sense for a lot of owners. Complaints include poor ride quality, expensive tyre replacement costs and the punctures you’re experiencing.

Even though the 50-series tyres on your car are not what most would call super-low profile, they don’t feature the same depth of sidewall as a `taller’ high-profile tyre. At that point, the sidewall has to be more rigid and there’s less flex in it. Which, in turn, makes the sidewall sometimes more susceptible to copping a stray rock or even a kerbside gutter and not being able to flex to prevent damage to the rubber itself. So, in some cases, going to a smaller wheel but a tyre with a higher profile (deeper sidewall) can be a good move.

What will limit this will be the brakes on your Tiguan. Fundamentally, you need to have a wheel rim with a large enough inside diameter that it clears the brake calipers. If the wheel diameter is smaller than the brake package, you physically won’t be able to fit the new wheel-tyre combination. There are also the issues of ground clearance and speedometer calibration, both of which can be compromised with a different wheel-tyre package and, therefore, a different rolling diameter. The trick is to use, say, an 18-inch wheel and match that with an 18-inch tyre that has a deeper sidewall that gets you back to the original tyres’ rolling diameter. That will retain your speedo accuracy and your ground clearance and should also give you a tyre that’s less prone to sidewall damage and cheaper to replace if the unthinkable does happen again.

A good tyres shop should be able to help you with the necessary measurements and sizing.

The upgrade to your navigation system can be done at a Volkswagen dealership and would be part of the work carried out at your next service (assuming you use a VW workshop). What most people tend to find, however, is that the Tiguan’s Apple CarPlay facility allows you to use the navigation services on your phone which, based on consumer feedback, are more accurate anyway since they’re updated in real time.

Your car’s sat-nav should be taking its data from an SD card that’s inserted in a slot inside the glove-box. So, the first thing to check is that the SD card is seated in the slot correctly. But there have been cases where the VW’s software seems to have a light-headed moment and loses the plot (it happens on plenty of other brands, too). One thing you can try is to press the on-off button for the infotainment screen and hold it down for at least 15 seconds. Sometimes, that will actually reboot the system and everything will come to life again, including the sat-nav.

Failing that, it’s a trip to the dealership to have the experts fix it. It may turn out that your data card or the software in the car needs an upgrade, which the dealership should be able to sort out for you.