europeankar

Hey folks,

Thinking to come back to the AMG world. I am currently in the market for an A45 or M235i. 4 cylinders vs 6 cylinders, dual clutch vs 8 speed auto, AWD vs FR, and true AMG vs none M power. I heard the throttle response is slower in the M133 compare with the bigger displacement N55? DCT in the merc is not fast in manual mode in downshifts? Why A45 and M235i? They have the same price tag here. Technically, A45 and CLA45 is pretty much the same car. Thanks for any inputs!

Zeee_Q

I'm not sure what the throttle response is like on the M133 motor, but I dare say it won't be as fast or responsive as the N55. The N55 hits full torque at 1200 RPM so virtually no lag and is silky smooth. Plus, the N55 has been out longer and it's already been proven capable of over 400 whp.

The transmission is a bit of a toss-up. The dual-clutch is great as it's faster and has launch control, but the ZF-8 speed in the M235i is not much slower and also features a version of launch control.

The M235i will naturally feel better when the road gets twisty since it's rear-wheel drive, but if you only care about straight-line speed then the A45 may be the way to go with all wheel drive.

AV1

Hello there

That's an interesting comparo you've set yourself...

I've got lots of experience with the early release 135i which was powered with the N54 as you would know pretty much similar power and torque output to the newer N55 but utilising smaller twin turbos and fixed valve train compared to the larger single turbo and variable valve train of the N55, I've driven the 3 series 335i with the N55 and it felt very similar to the earlier 135i with the N54, just FYI both the N55 and new M133 actually share the same turbo unit AFAIK the BW B02.

I've also extensively test driven both the A45 and CLA45 AMG's.

From my experience the N54 and N55 are very responsive engines with loads of low end torque, the smaller M133 doesn't have the same shove at low speeds but in an overall performance comparison the A45 and CLA45 I've driven are easily much quicker and faster than a 135i with the N54 or 335i with the N55 that I've driven, the A45 will also run rings around just about anything in the handling department, I can't believe how aggressively you can throw this thing around at extremely high speeds and still be in full control - it's sensational !!!

I can't comment on the 235i as I've yet to try it out, but it should be a step up on previous N55 powered Beemers because the output is up and the newer Beemer 'should' have better dynamics than the previous models.

It all comes down to what you really want, these cars are all very different bodies to begin with, in the same price range for you as you mentioned the new 235i is a coupe, the A45 a hatch, (CLA a sedan) so are you seeking a specific configuration / layout / look or do you just want the best performing one regardless of body shape ??

My advice try take each of them for a whole day or better whole weekend test drive them to thoroughly compare, you'll then be able to make your own judgement on the differences and make your choice from there, don't worry too much about what other people say, just choose what's best for you

europeankar

Thanks a lot for the information. I'll be getting a test on the A45 in a few weeks and there is no test drive for the M235i. I will be selling my E92 M3 DCT soon. I really dislike the lack of the torque in city driving which occurs 95% of the time. I will have to decide which car I like more. Both are excellent little cars.
N54 and N55. Aren't they like getting dated?

Zeee_Q

The N54 is a bit dated and is well known for carbon issues on valves. Plus it lacks Valvetronic which the N55 has. The N54 does currently have more tuning potential and options out there compared to the N55 which has proven to be troublesome to tune at times. BMW did put a stronger crankshaft in the new M235i due to the increased power I suppose, but besides that and a bigger(4 inch) electronically controlled waste gate, everything appears the same.

There is also rumor that BMW may be shifting back to a 3L I6 twin turbo engine based on the new M3/M4 engine, but obviously in a de-tuned manner in order to cut costs. So essentially, there will only be 3 engine line-ups in BMW. The 2.0L I4, 3.0L I6, and 4.4L V8.

AV1

The N54 is getting on a little now but I wouldn't call it a dated powerplant it is still very competitive especially with aftermarket tuning.

The N55 is newer and as mentioned will feature more new parts as it continues life in new BMW models.

I understand what your talking about with a lack of low end torque in high power N/A engines of smaller displacement like that in the E92 M3 I've driven one and it does feel weak unless you thrash it - it's one of the main reasons I decided on a high power diesel as a daily driver, my C250-CDI tuned has over 600nm torque at just 1500rpm making it a perfect and super quick daily driver for about 90% of my everyday driving conditions, a forced induction N54 or N55 powered Beemer will feel stronger off the mark than the M3 and much better suited to daily driving conditions, or if you a large displacement N/A V8 such as the #63 in AMG's or like an LS1 which I have in one of my other cars, they produce high low end torque.

Certainly do test drive the A45 and then wait untill the 235i is available and do the same with that vehicle - preferably back to back or on the same day would be better to get a much better idea of how they compare, if you test drive weeks apart you may not remember exactly some of the aspects of the drive, after that it's decision time

The N54 is also notorious for fuel pump failures and it seems to have spread to the N55 but with lesser frequency.

There have also been issues with the N54's twin turbos as well, they are actually of Japanese make and origin AFAIK Mitsubishi units...with the N55 BMW have reverted back to Borg Warner with the B02.

It does look like BMW will use a 3.0ltr IL6 twin turbo for their new M3 previously the rumor was a tri or triple turbo IL6, but to date that has only eventuated for their new 3.0ltr IL6 tri turbo diesel.

BuckeyeBenz

I have been reading up on the new M3/M4 and that engine will use the Mitsubishi turbos as well. Is that the same manufacturer as the car company?

http://f80.bimmerpost.com/forums/sho...d.php?t=923203

That would really concern me if I were in the market for the new M; why would bmw use turbos from a company that they had problems with in the past?

kimeran

I know the new M6 has Garret turbos....SO I would assume the M3/4 would use the same?

AV1

Yes same manaufacturer which are a part of parent company Fuji Heavy Industries.

Hopefully they've improved with fewer/no issues, the issues they had with the N54 were mainly to do with the HPFP (fuel pumps) as mentioned in an earlier post.

It's not something new that companies from different nations share or use each others hardware or parts and even paint duco, my/our beautiful 'diamond white bright' MB duco is from a Japanese manufacturer

AV1

AFAIK different engine (V8 vs IL6) so maybe different spec/requirement for air flow/boost etc. as needed for that engines performance regime determines what turbos are used.

It'll be interesting to see if the new MB AMG 4.0ltr V8 adopts the same turbos as the M133, as we already know a lot of the internal components will be shared between the new engines, the new V8 will basically be a M133 doubled up.

zibby43

I've had experience with both stock and tuned N54s and N55s.

That motor is something else. The N54, in particular. My Stage 2 Dinan '07 E90 335i was an absolute torque monster. I could light up the rear tires on that car just as easily as I can now on the C63. It's only problem/flaw was that it started to run out of breath a bit at the top end.

The 8-speed ZF "Sport Auto." transmission I had on my M Performance-tuned F30 M Sport 335i was one of the best transmissions I've ever used. Upshifts and downshifts were lightning fast. That transmission paired beautifully with the N55.

AV1

Absolutely totally agree on the ZF autos - they are fantastic transmissions !!!

Even the previous 6spd auto as used in earlier 135i's and 335i's and most other BMW's I've had experience with were as good or better than similar model year DSG type transmissions from other companies, the new 8spd is even better as you pointed out, it even contributes in making a new model bottom of the range diesel powered BMW 118d feel fast due to the ratio spread and lightning shift speed.

I kind of wish MB also adopted and used the ZF transmissions in their cars, just about everyone else does and it makes their cars perform a lot better because of it.

Otherwise hopefully MB produced transmissions will improve in future, from what I've seen and read up so far on the new MB 9 speeder it doesn't seem to be much of an improvement on the current 7GTronic.

zibby43

Totally agree. MB should stop tinkering around with their own proprietary transmissions and just outsource like BMW and Jag.

I can't even imagine how much better the C63 would be with the ZF 8-speed Sport Auto.