420R onboard

Caterham Seven 310R: Part three – 310R or 420R?


How does the Caterham Seven 310R compare to its bigger brother, the 420R?

It’s been a week since we told you all about how the new Caterham Seven 310R drives, so in this week’s article we thought we’d compare it to its more powerful sibling – the 420R.

Though they share the same DNA, they are cars with very different characters and, like many performance vehicles, you need to spend a bit of time with them before you really start to understand them. Thankfully, I’ve being doing just that.

420R side

Earlier this year I was lucky enough to drive the Caterham 420R all the way from Land’s End to John O’Groats, in the process exploring how this type of car performs outside its comfort zone. That particular car was a yellow ‘SV’ – SV being the code for the larger chassis. It’s much better for taller/larger drivers, giving more room inside and extra fuel tank capacity, but obviously a larger chassis adds a little bit of overall weight to the car. The larger 2.0-litre Ford Duratec engine in the 420R does too, so with the ‘SV’ chassis and larger 2.0-litre unit, Caterham estimates that the 420R was around 35kg heavier than the new 310R we’ve been testing.

That brings me to the most noticeable difference between the 310R and 420R – the 35kg or so of extra weight. In any normal car you wouldn’t notice 35kg, but in the featherweight Caterham Seven you notice it almost immediately. It shows up most prominently in corner entry and maneuverability at speed, and while the 420R is about as far away from clumsy as you can get, the 310R has that little bit more speed available in directional changes, and is quicker to reach an apex than its bigger brother. Put simply, it’s a little bit sharper.

420R onboard

The 420R makes up for being a little heavier and slightly less wieldy than the 310R by having 210bhp, almost 60bhp more than the 310R, and as with the kilograms, you feel every single one of those horses too. Acceleration in the 310R is rapid, but in the 420R it is brutal. If you can control the lively rear end, 62mph is reached in under 4-seconds, putting it into the same division as most supercars. Using that power is an incredibly addictive sensation, but one that requires responsibility and a certain amount of driver skill to accurately deal with. It is quick to overload the rear-wheels, especially on wet roads, and that’s despite wider wheels and Avon ZZR tyres being fitted than those that found on the 310R. While the 310R’s Avon’s may be slightly thinner, its rear-end holds onto the road more eagerly and it feels more natural to be dealing with 150bhp.


We have to be mindful of what we’re comparing here – these are two near-identical ultralight British sports cars that when compared to just about any ‘normal’ sports car feel positively lightning. But, in comparing them to each other it’s clear that they are quite different – on the road at least. The Caterham that will suit you most depends on what you really want to use it for. A torquey 420 has a better engine for longer distances and straight line performance, but the more nimble 310 is a more natural fit for the original Caterham recipe, and more enjoyable to thread sweetly through the corners.

So, do you think you know what you’d prefer in a Caterham? If you do, there’s a fair chance that you’re ready to make a call on which Caterham model to buy. If that’s the case, you should catch next week’s article where we’ll provide some tips for specc’ing and buying your very first Caterham.

caterham 310r