Interesting. Motoringfile is reporting that MINI USA is introducing a revised engine for the 2015 MINI Cooper S. The MPG maybe improving but not the HP.

http://motoringfile.com/2014/09/10/m...mini-cooper-s/

The EPA delays that MINI USA is dealing with may have roots in the fact that 2015 sees a new version of the Cooper S four cylinder. The B48 has quietly made way for the B46 – a variation of the 2.0L which is a classified as a super ultra-low emissions vehicle by the EPA (SULEV). What does this mean to potential owners? Read on.

For starters the 2015 Cooper S could have slightly better MPG numbers because of this change. But those hoping for more power will have to wait for the 2015 JCW. The B46 is rated at the same 189hp and 207 lb-ft. torque that the B48 had.

The 1.5L three cylinder remains unaltered for the 2015 model year.

 

It was discussed some time ago in this thread:
https://www.northamericanmotoring.co...46-vs-b48.html

 

Kinda curious as to what the actual differences in this motor are

 

So, B48 is used for only one model year?!
Curious to know what the difference is and what was done to increase the MPG.
Couldn't be too much different though since it's only a year apart.

 

Probably just an EPA change, I'm sure it's just running the motor a little leaner to recuce emissions.

Maybe it will be better having the older motor

 

Both of the above articles discussing the B48 to B46 only state a change in EPA
and perhaps a slight change in mileage.
There are no definitive changes, that leaves us to speculation...ONLY.
A remap to lean out the fuel mixture? = better mileage, =fewer emissions, =less OOMPH ?
Sounds like the B48 might be the engine to have, so put your 2014 away, buy a 2015
to drive and watch the 2014 value accelerate LOL.
Think I'll just get a 356 Roadster.

 

Also, Too Lean = More Likely to Detonate!

We 2014 B48 owners should consider lucky!

 

The engine to have will be the JCW. That's not a tune, it's a different turbocharger.

 

Lack of information is ridiculous.

If it is part of the EPA troubles, it doesn't explain my 3-cylinder being held.

 

Yessir, that is a fact..!! I love the B48, just the way it is.

 

if it were simply leaner a different tune is all it would take, not a different engine

 

Has a different code at least, called B46!

Isn't higher the number better or more refined, especially in engine codes like LS1, LS2... LS6?

 

Lower emissions, better fuel economy and the same HP and torque is bad because.....?

 

Says Kyoo
"if it were simply leaner a different tune is all it would take, not a different engine."

It is not a different engine physically. The pistons, heads, crank etc. are the same, however the "intellectual" operating parameters are changed.( A remap?)
Does that make it a different engine? In some respects yes, in most respects no.
Know?

 

I saw this news as well. Is the change happening for all 2015 MCS models? Still waiting on my 2015 Roadster to get to dealership.

 

No, this only affects the 2015 F56 Hardtop model. Your Roadster uses the PSA "Prince" engine, which would have an engine code N16 (Cooper), N18 (Cooper S) or N18 (JCW).

 

please tell me you're kidding.

the people working at BMW know a lot more than we do so I'm sure they realize that running "too" lean can be dangerous.

as far as "too" lean, the first generation Honda Insights had a lean burn mode that was 25.8:1, so it is possible to make a car run "too" lean when cruising.

 

Too Lean?
Speculation only
We don't know what changes have been made
Perhaps they will be delineated?

 

Not to be that guy but a 2015 JCW would have the N18 engine.

 

The JCW is sticking with a 1.6? I wouldn't feel so bad for just buying an S if thats the case

 

Sorry if I caused confusion, the JCW Hardtop does not have the N18 engine, just all the other JCW's for the 2015MY

 

I think all of the 2015 JCW cars have the same engine, the N18, same as the 2014 JCWs. The F56 JCW won't be out until next year and will have the 2L engine, but it could come as a 2016 model we don't know for sure yet.

 

That would align exactly with what I said yes.

 

PLEASE be that guy! My typo ... I initially wasn't going to include the JCW, and then when I added it, my momentary brain lapse hit the wrong number. Thanks for catching that. I corrected my original post.

 

All R (Rover) series JCW models have the PSA (Peugeot-Citroen) "Prince" N18 motor. R55, R56, R57, R58, R59, R60 and R61.

All F (BMW) series upcoming 2016 JCW models will have a modified 2.0l turbo B48B20O0 motor from the 2er BMW Active Tourer.

Dust settled ...