Of the two cars you mention, the Suzuki will probably get the best real world fuel economy, but both these cars are mild hybrids that make nominal fuel savings of about 5mpg. For a significant saving, you'll be better off with a full hybrid such as the Toyota RAV4 – you don't plug it in, but its larger battery and motor mean it can travel for a few miles on electric power alone, unlike the Suzuki and Renault. Your budget will get you a 2016 RAV4 with highish miles, but Toyotas are know for their reliability and their hybrid systems are also very robust. It's a comfortable and practical car. Here's our review: www.honestjohn.co.uk/carbycar/toyota/rav4-2013/