IT'S testimony to the design of Jaguar cars that they evolve rather than transform when it comes to update time.

The latest to hit the evolution trail are top sellers for the great British brand - the XF sports saloon and estate and the F-PACE SUV.

Both models get some striking design changes inside and out but both remain instantly recognisable as cars of the time - which in the case of the XF started back in 2007.

There are new bumpers with larger air vents, a new grille, narrower LED lights front and back and all in all both the XF and the F-PACE look more assertive.

But it's on the inside where the greatest changes come and both models now share the same dashboard and instrumentation which includes Jaguar's latest Pivi Pro infotainment system controlled from a new-look 11.4-inch touchscreen that sits proud in the centre of dash.

There's also a fully interactive 12.3-inch instrument panel ahead of the driver, a new look to the centre console and a completely different gear selector that replaces the previous rotary control with a chunky lever complete with cricket ball-like double stitching.

And there's no handbrake button or lever with the vehicles now being secured via the P button alongside the transmission - a trait that is going to make its way to all JLR models fitted with an automatic gearbox.

Realistically, the only difference to the front interior treatment on the XF and F-PACE is the seats which on the SUV we sampled were of lightweight sports design beautifully finished in red leather.

The XF line up now starts from £32,585 for a diesel-powered D200 saloon with the Sportbrake estate coming in from £37,735 in similar specification.

Petrol models cost from £33,925 with P250 powertrains with the Sportbrake priced from £39,275.

The saloon we tried - all models were left hand drive - was an all-wheel-drive P300 in R-Dynamic SE trim which comes in at £41,850.

With a 2.0-litre, four cylinder Ingenium engine under the bonnet it packs a mean punch, accelerating from 0 to 60 in 5.8 seconds with a maximum of 155mph.

From a fuel economy perspective it is rated at 32.9mpg officially with emissions of 193g/km and we managed to average 29.2 to the gallon with the diesel Sportbrake much more economical at 37 to the gallon.

The Sportbrake was a rear-wheel-drive D200 officially rated at 54.2 to the gallon (137g/km) and it's no slouch either at 7.3 seconds 0 to 60 with a top end of 143mph.

When it comes to the F-PACE the car now looks much more the part with bigger front air vents, new-look headlights and a fresh design to the bonnet.

The version we tried was a six-cylinder petrol P400 model with a mild-hybrid Ingenium engine giving the car a 0 to 60 acceleration time 5.1 seconds and a maximum of 155mph.

In top-but-one R-Dynamic SE specification it's priced from £61,115 although the new F-PACE line up can be had from £40,860 which will buy a 163ps diesel.

Fuel consumption on the P400 is rated at 28.8 mpg with emissions of 221g/km and over a similar route to the XF we achieved a credible 25.7 to the gallon.

All the newcomers have nine-speed auto gearboxes allied to paddle shifters for sporty manual selections and the box is a gem on the move with multi-mode drive programmes to get the best out of the performance.

Features such as head-up displays, wireless phone chargers and a new active noise cancellation system for the cabin can be had and so can JLR's Clearsight rear view camera system which replaces the standard view in the mirror with a camera display.

It's all very state of the art and beautifully crafted in true Jaguar fashion.

With a full range of powertrain options - including electrified plug-in hybrids - available both the XF and the F-PACE remain' top of the tree' models in their respective sectors and good enough to give any German rival a run for its money.

Subtle the changes may appear but they pack a punch when it comes to all-round appeal and make Jaguar's evolution as special as it always has been.