The BMW 5 Series is an institution. Since the first model was launched in the 1970s, it has been the definitive executive saloon – and each passing generation has brought a collection of incremental improvements to make it more comfortable, more efficient and more technologically advanced.

Crucially, the spirit of the BMW 5 Series has remained consistent over the past 50 years. It’s always been a practical family saloon with a great range of engines and an engaging driving experience – and BMW has worked hard to adhere to that brief for the new car despite the fact it’s now working with a new electrified platform.

This the most electrified 5 Series BMW has ever made. Every petrol engine in the saloon’s range is now supported by some form of electric motor and, at the top of the line-up, there’s a choice of two pure-electric variants (which you can read about in our dedicated BMW i5 review). Mechanically, it’s a stark departure from the old 5 Series – so, it’s a good thing that BMW played it safe with the new car’s styling and interior.

Allow us to elaborate. Cars such as the 4 Series and 7 Series (with their truffle-snouting nostrils) can afford to be adventurous because the market they’re aimed at is quite small. But the 5 Series has an almost limitless appeal, meaning it would have been foolish for BMW to take a risk on this new car’s design and functionality. After all, the 5 Series is still one of the brand’s biggest breadwinners.

Happily, such sensible thinking has produced a rather brilliant car. This might be the biggest, heaviest and most complicated 5 Series to date, but it still hasn’t lost the essence of what made its predecessors so good. It’s still comfortable for you and four passengers, it’s easily practical enough for family life and it can still thrill you when you get it on a stretch of twisty road.

But, like almost every other consumer product, the cost of the 5 Series has inflated for this new model, with prices for the most basic 520i starting from more than £50,000. It gets worse as you ascend the pecking order because, if you want the plug-in hybrid 550e we’ve tested here, you’ll be looking a bill of almost £80,000 before options. Add a few extras and you can ratchet that figure perilously close to £100,000.

The question is – is the new 5 Series good enough to justify its steeper price tag? Or would it be wiser to opt for a cheaper rival, such as the all-new Skoda Superb or the aging Jaguar XF? Read on to find out what our team of expert testers think – and if you want to learn more about our process, check out our page on how we test cars.