It's not that long ago that you'd have laughed at the idea of comparing a Ford to a Mercedes. Some may still. But from the moment Ford (under the Lincoln nameplate) threw its hat into the full-size sedan ring with the MKS, it became a true player in this segment of the car market. Gone was the classic Town Car – an anomaly that, despite being in the full-size sector, actually had no true rivals other than its siblings the Ford Crown Victoria and the Mercury Grand Marquis. The MKS, by contrast, is a serious contender – as is its Ford stablemate, the Taurus.

By becoming a badge-engineered MKS, the Taurus nameplate has leapt from the midsize range to full size and it is a substantial car in every sense. In SHO form with a 3.5-liter 365hp Ecoboost engine, as tested here, it's quick, too. In size terms, the Taurus's rival in the Mercedes-Benz range is the S-class, but no one who has $92,000 (MSRP for the cheapest S-class) to spend on a car is going to look at a Ford that retails (before options) at $39,000. Even a Lincoln MKS with the same engine as the Taurus SHO is only $49,800, and so there's probably too much of a perceived brand value difference to persuade a Benz user to switch to a Lincoln. But, switch down a size to the E-class, and you have the E350 sedan, complete with normally aspirated 302hp V6 unit, available from $51,000.

Given their proximity in price, many would-be Linc owners would find the extra grand or so for the Mercedes. But the Taurus SHO makes a more convincing argument: can the German car really justify a $12,000 premium over its notably faster and more commodious American rival?

It's worth noting, that neither of our cars were in standard form – the Ford has around $5.5k of options, the Benz $7k. And it's too boring to list them, so on the next page, you'll find pics of the option spec sheets.

Judging the cars aesthetically is an interesting task now that both are such familiar sights on our roads, but it's safe to say that neither would be considered for the Museum of Modern Art. A Taurus, in standard form, looks like the offspring of a relationship between the outgoing Ford Fusion and a Chrysler 300, and it struggles to hide its mass, despite that deep ridge that breaks up the large expanse of metal on its doors. Nonetheless, the SHO's details do add an aggressive look that's missing from the lower-powered models.

As for the E-class, well…no matter how many lines have been carved into it (and yes, I do like the one that curls over the rear wheel arch in homage to the early-'60s “fintail” M-B sedans), the wheels look too small for the amount of metal on show in side profile. Its predecessor was a far more handsome and timeless design, in this writer's opinion. But that's the point: aesthetics are a subjective matter.

By contrast, it's an objective statement to say that, from its superb paint finish, shut lines and chromework, the E-class is a reminder of how Mercedes-Benz gained such a huge following around the world. The same is true inside where its materials look and feel top quality, and yet aesthetics haven't come at the expense of ergonomics: with one notable exception, everything is laid out in a logical manner. That exception is the cruise control lever on the left side of the steering column which is set just above where you'd expect the turn signal stalk to be. That device, meanwhile, sits too low. (OK, so most Mercedes owners will be familiar with those locations by now – M-B models have had that layout for years – but that doesn't make it logical.) That aside, the overall impression is to be awed by the fact that this is a so-called base model of the E-class lineup.

It's a testimony to the vast and regular improvements Ford has made to its interiors in the last dozen years that the Taurus is not totally outclassed. What it lacks in top quality materials, it makes up for in sophistication and thoughtful design, and while the touch pad on the center console does drag your eyes from the road because there's no positive feel to control activation, this is something that would, one assumes, become more instinctual during long-term ownership.

What can't be denied is that the car feels as solidly screwed together as the Mercedes. Driving over some terrible roads during the course of the test, there wasn't a rattle or squeak to be heard inside despite the low-profile tires and stiff suspension of the SHO. On the subject of interior layout, one other subjective matter must be raised: having the gearshift on the transmission tunnel, as per the Taurus, is still more user-friendly than the steering column stalk of the Mercedes.

Something that has always marked out Lincolns from Fords is superior suppression of engine noise, but one assumes if you're going for an SHO Taurus, you want to hear that V6 turbo play its tune when accelerating hard, but barely hear it when cruising at 80mph at around 2000 rpm in top (sixth). In which case, both jobs done commendably well by the Ford engineers. You wouldn't expect a car that launches you to 60mph from standstill in 5.2secs and runs low-profile tires to be such a civilized cruiser or so good at avoiding tramlining in the gullies dug in roads by semis.

The Mercedes, predictably, is a similarly enjoyable place to spend long distances on the freeway but its 7-speed gearbox, while doubtless improving its fuel economy and emissions, is all-too-ready to drop a cog rather than use its 273lb-ft of torque. And the 3.5-liter engine is surprisingly loud. It would be a step too far to suggest it was coarse, but there are definite occasions when it seems to be making a whole lot of fuss about not a whole lot of acceleration.

This view has been colored by the fact that we also tested the E350 BlueTec diesel, and that is a peach of an engine that delivers 400 lb-ft of torque. If it lacks the gas-powered brother's absolute punch – it has only 210hp – its torque ensures this will not be noticed in day-to-day driving. Truly. And anyway, it's still quick enough to duck under the seven-second 0-60mph barrier.

In our hands, the diesel had vastly superior economy to its gas-powered counterpart, despite Mercedes' own city/highway mpg  figures noting a small difference – 19/29 for the E350, 22/32 for the diesel. Official figures be damned: the BlueTec car went so long between fuel stops I always had to re-check which side the filler cap was on. And that engine chitter-chatter which anti-diesel ignoramuses warn you of can only be heard outside the car and only at standstill.

But both Es would fall short of the Taurus SHO if this was simply an assessment of straight-line capability, because of the Ecoboost engine's enthusiasm and refinement,  the slick nature of its gearbox and the fact that returning just 17/25mpg is a price most would be willing to pay as compensation for its performance and lower purchase price. It also feels very roomy. The Taurus supposedly has marginally less headroom in the rear than the E-class, despite its size, but the extra couple of inches in rear legroom are much appreciated.

Given this writer's 6ft- 3in. height, the driver seat in most cars needs to go back as far as it can. So anyone sitting directly behind me in the Mercedes needs to be 5'6” or less, especially when the seat backs are hard plastic (what's that all about, by the way?). The Taurus, by contrast, can easily accommodate long-legged rear seat passengers.

And so it should, given that the Ford is 11 inches longer and almost three inches taller than the E-class. It also has a far larger trunk – 20.1 cu. ft to the Benz's 15.9. The inevitable penalty is that it's over 500lbs heavier than the E350 and this does hurt its agility. If the Mercedes is a little too vocal in the engine department under hard acceleration, it's hard cornering that creates the aural cacophony in the Taurus as its mass pushes the 245/45R20 tires to their limit.