MINI’s Revised 2011 Engines In Depth

(The following article is a revised version of what was published last week in the MotoringFile Countryman review)

Starting with September production MINI will be substantially revising the entire range of cars for the 2011 model year featuring smoother operation, higher efficiency and more power. In the US and Canada this means that MINI will be rolling out the engine updates that were first debuted in March builds for the European market. We’ve detailed the 2011 refresh in many articles over that past several years, this article will focus on the changes to the 1.6L powerplant found at the core of every MINI model. There are some exceptions; we are not reporting the upcoming refreshed JCW version of the engine because we don’t have information on it yet. However rest assured as soon as we get it, you’ll read it on MF.

First the Cooper. The R60 Cooper has 122 hp up two from the previous configuration of the naturally aspirated Prince engine. Yes it’s just a slight increase but there are a lot of changes under the surface. The naturally aspirated 1.6L gets a new map regulated oil pump that adjusts pressure and volume based on needs of engine (and not just engine speed as before). It results in a 3% fuel savings and allows for the whole system to heat quicker in cold weather (due to it not engaging in cold starts when it’s not needed).

The MPG ratings haven’t been released yet but we expect final figures to be around 2 mpg higher on the highway.

Even more impressive is what MINI have done to the Cooper S. Yes there’s more power, but lets focus on efficiency first. The R60 MCS will reach the same mpg (not a typo) on the highway thanks to a more substantial upgrade. In fact CO2 levels go from only 140 gm to 143 despite the turbo and the extra 60 hp. The MCS sees all the same updates that the Cooper gets but with the major addition of fully variable valve train (Valvetronic as BMW calls it) along with refinements of friction point throughout the engine. The result is an increase of around 10hp for approximately 182 hp (final US figures are forthcoming).

Valvetronic gives the Cooper S the ability to rev quicker, deliver more power yet achieve better miles per gallon. A win win by all accounts.

When I spoke with the MINI engineer that lead the development of the revised engines, he noted that all of these additions to the range are patented and will only show up in the MINI range. I probed a bit more and he expanded on the relationship with PSA a bit. For one BMW handles all development separately and in fact PSA is only in charge of purchasing components. All Prince engines are assembled in the UK at Hamms Hall with only the block coming from France. Additionally he pegged the ratio of British to French parts at around 80/20.

And that cold start issue? It’s eliminated with the new engine. For the sake of the MotoringFile reader I continued to press him a bit and he let slip that the issue was caused by a production problem from a supplier. However problems with current engines have been rectified with a fix sent to dealers earlier this year according to the engineer.

How is this new power translated to the road you ask? It was impossible to feel the difference in acceleration (and power) between a 2010 Cooper S and the 2011 Countryman Cooper S with the new engine simply because of the added weight the R60 carries. However I could detect a difference in the eagerness of the car to rev and some subtle changed to the clutch and shift feel.

The transmissions also see some substantial revisions on the 2011 models as well as the Countryman. The Countryman features unique ratios and a taller shift lever but aside from that all changes carry over to the 2011 models as well.

The biggest upgrade is the entirely new clutch that is now self adjusting. This provides a more consistent pedal feel and we’re told should be a little more robust than the previous version. The flywheel is now a dual mass unit that adds a bit more comfort in regards to smoothness and sound. Also new are carbon based shift cables that add an even smoother feel and should last the life of the car.

The result is gearbox that feels even more slick than before. While it lacks the positive feedback of some of the better BMW gearboxes, it’s certainly a step up from any of the competition (I’m looking at you VW) and a noticeable improvement over the previous system.

The six speed automatic is also upgraded in several key ways. The biggest change comes with a system called neutral control. At idle (with your foot on the brake) the auto equipped Countryman (and any other revised 2011 MINI) will subtly de-couple from the previous engaged gear. Once you lift off the brake the transmission re-engages with the previous gear. The net result is a subtle gain in efficiency. In sport mode this system is off for optimized (and more immediate) acceleration.

Another improvement in the auto is stop and go detection which can tell when you’re in stop and go driving and change the shift program to stay almost entire in 2nd for smoother operation.