jlbbergerac

I wonder if any one can help me. I have a RHD 2005 Mitsubishi Shogun sport warrior 2.5td which has 18" alloys on it. These were standard on  the vehicle when i bought it in the uk. The car is now registered here in france but will need a CT on it soon. I have been told that it will fail as the car should have smaller wheels on it. The certificate of conformity says that it should have 15" wheels on it. Has any one else had a similar problem with this.