Automakers pushing to sell cars before new emissions rules come into effect helped to boost registrations in western Europe by 9.1 percent in July, according to market analysts LMC Automotive.
France and Spain saw the biggest growth in the region's top 5 markets, also helped by an extra selling day compared with July 2017. Both markets were up 19 percent.
Registrations in Germany, Europe's biggest market, increased by 12 percent, while in Italy sales were rose 4.4 percent,
The UK market grew by 1.2 percent, a modest increase after sales fell throughout the year impacted by a decline in demand for diesel cars and uncertainty over the outcome of Brexit talks.
In a news release, LMC said there is a "strong suspicion" that July's increase in western European sales is related to the Sept. 1 deadline to register cars under the existing NEDC emissions regulations rather than the more stringent WLTP legislation.
In Germany in particular, "the most likely explanation seems to be self registrations ahead of the WLTP deadline because there is no other apparent reason for the pace of sales to pick up so strongly," LMC said.
The analysts firm forecast "payback in the later months of the year, restraining growth for 2018 overall."
LMC expects the western European new-car market to grow by 1.6 percent this year to 14.53 million, boosted by strong performances of Germany and France.