[HighlandPete]

Originally Posted by 37psi

The acceleration between 100-120 also impressing. Alas it is performance best suited to the unrestricted autobahn.

High speed driving is where the bi-turbo engines really do excel. The engine choice debate has existed since the first 30d & 35d models have been around. Many (including myself) feeling we didn't see much difference in typical UK driving. Yes better at both the bottom and top end, not being in dispute. A forum member who was driving one of the first E60 535d models, much of the time in Germany, commented on how the real benefits were outside UK speed limits. The harder pull at speeds above 100mph, marked the real difference between a 530d and 535d, speeds we just don't use on public roads over here.

[HighlandPete]

Originally Posted by creepy coupe

When I had my 435d and would jump between it and a friends 330d X drive.. I found the 330d would change down in places under acceleration, where the 435d wouldn't. [B]So mid range torque makes a difference./B]

Agree on the mid range torque comment, most useful in a manual. The 8-speed auto box even blurs that difference in our latest cars.

[creepy coupe]

Originally Posted by HighlandPete

Agree on the mid range torque comment, most useful in a manual. The 8-speed auto box even blurs that difference in our latest cars.

Yes the 8 speed auto makes a great job of masking engines that are not as good as they could be. The 2.0d with the manual is a pig. But very nice with the auto.

[Dr Forinor]

Originally Posted by HighlandPete

The extra weight of the 335d is all over the front axle as well, so it is a compromise, more so if we don't need the benefits of xDrive for most of our driving.

Weight and extra xDrive losses do cost us both in acceleration times and fuel economy. Steady state driving may not be too big a penalty, but on acceleration, getting more weight and extra rotating masses up to speed are parasitic losses, adding to a higher road load.

I think you have hit the nail on the head there.

Like I said before, I'm glad I bought this car, because otherwise I would have been like "if only I had got the 335d", and it would bug me. I have it out of my system, next time I am sticking only to an sDrive model.

If it will be possible to buy a x35d in sDrive then I may consider it, otherwise x30d with sDrive.

[Soul_Glo]

So does a remap make sense for a 35d? If the best work of the bi-turbos is above 100mph?

[Dr Forinor]

Originally Posted by 37psi

So does a remap make sense for a 35d? If the best work of the bi-turbos is above 100mph?

For me, I felt a difference after the remap, across from very slow to very effin fast

[Hooded]

Originally Posted by 37psi

So does a remap make sense for a 35d? If the best work of the bi-turbos is above 100mph?

A remap always makes sense
Besides it will improve performance in It's weaker range like 30 -70mph for example and stop a well remapped sdrive 330d pulling away from you a little

A stock f30 335d can barely pull on my remapped 320d 80 -110kph .. they really are weak for the power and overall performance of the car in that range, ..a remap fixes that though

[Ajs_435d]

The thing is the x35d will make max boost at pretty much at any RPM (well above 1200RPM IIRC) so initial acceleration will be quicker that's the point of the turbo setup as well as good low down and high up performance, the 330d will need time to spool (not that its slow) and will die off earlier.

I'd love to see the drive train loss figures as its been banded about on here, between RWD and 4WD - in reality its only a couple of percent which translatea to not massive power deficit.

In all honesty I'd be more than happy with a remapped 330d, but i think my next car will be some sort of performance hybrid.

[Hooded]

Originally Posted by Ajs_435d

The thing is the x35d will make max boost at pretty much at any RPM (well above 1200RPM IIRC) so initial acceleration will be quicker that's the point of the turbo setup as well as good low down and high up performance, the 330d will need time to spool (not that its slow) and will die off earlier.

I'dlove to see the drive train loss figures as its been banded about on here, between RWD and 4WD - in reality its only a couple of percent which translatea to not massive power deficit.

In all honesty I'd be more than happy with a remapped 330d, but i think my next car will be some sort of performance hybrid.

I appreciate the debate about drivetrain loses, and loses through the extra weight, but whether it's 2% or 10% in reality performance doesn't ever lie, and there is more than a couple of percent performance loss from a rolling start in the midrange on xdrive.

This gives a rough idea..
http://www.zeperfs.com/en/duel5992-5613.htm

[Ajs_435d]

Originally Posted by Hooded

I appreciate the debate about drivetrain loses, and loses through the extra weight, but whether it's 2% or 10% in reality performance doesn't ever lie, and there is more than a couple of percent performance loss from a rolling start in the midrange on xdrive.

This gives a rough idea..
http://www.zeperfs.com/en/duel5992-5613.htm

True, the issue with that (not fully accurate) is it shows fly wheel power crank whatever you want to call it and if we mention drivetrain we need to look at wheel horse power/torque thus put down on the road.

[HighlandPete]

Originally Posted by Ajs_435d

I'd love to see the drive train loss figures as its been banded about on here, between RWD and 4WD - in reality its only a couple of percent which translatea to not massive power deficit.

So we take a 330d RWD vs. a 335d xDrive and get 50 - 75mph figures through the gears. The extra 55 HP only gives ~0.2 second improvement, in that mid range, 'through the gears' acceleration. Where's most of the 'extra' 55HP going? Extra weight, drivetrain and parasitic losses under acceleration conditions.

Take the directly comparable 330d RWD vs. 330d xDrive, and expand the in-gear increments to 50 - 112mph. Very clear the weight, drivetrain and parasitic losses are not insignificant, xDrive "as a package" adds 2.3 seconds.

Drivetrain losses are not fixed, a percentage, or linear, it's a most complex and misunderstood subject. Steady state losses have little bearing on the losses while under (hard) acceleration.

[JD6]

Despite liking the 30d, I'm surprised by the suggestion on this thread that the performance difference is narrow. It doesn't feel like that.

ACS indicate that the 330d sDrive takes 14.9 seconds from 80-180km/h versus 11.8 seconds for the 335d. Quite a difference. Admittedly this includes a small element over 100mph

http://preisliste.ac-schnitzer.de/ac...01&ID_NR=11645
http://preisliste.ac-schnitzer.de/ac...00&ID_NR=10315

[Ajs_435d]

Originally Posted by HighlandPete

So we take a 330d RWD vs. a 335d xDrive and get 50 - 75mph figures through the gears. The extra 55 HP only gives ~0.2 second improvement, in that mid range, 'through the gears' acceleration. Where's most of the 'extra' 55HP going? Extra weight, drivetrain and parasitic losses under acceleration conditions.

Take the directly comparable 330d RWD vs. 330d xDrive, and expand the in-gear increments to 50 - 112mph. Very clear the weight, drivetrain and parasitic losses are not insignificant, xDrive "as a package" adds 2.3 seconds.

Drivetrain losses are not fixed, a percentage, or linear, it's a most complex and misunderstood subject. Steady state losses have little bearing on the losses while under (hard) acceleration.

I think you've miss quoted me, I agree the differences are small but these massive drive train figures losses banded on here is what I was commenting about.

I agree (varying factors like tyres bearing etc) it's a rough estimate but it's the best rough estimate you'll get based on rpm/speed unless we take the engine out and bench dyno it

However I believe that the xdrive can transfer power from f/r but still has connections/losses?

In black and white a x35d is faster but not by a great margin and as the op found out in real terms.

I wanted a 4wd because I'm self employed and if I don't go to work I don't get paid ha.

[HighlandPete]

Originally Posted by Ajs_435d

True, the issue with that (not fully accurate) is it shows fly wheel power crank whatever you want to call it and if we mention drivetrain we need to look at wheel horse power/torque thus put down on the road.

When we talk about wheel horse power vs. engine horse power, are we calculating it under acceleration, or at a steady state? An engine at peak power, (or any other power output for that matter) holding a theoretical road speed, has got 'x' amount of drivetrain losses, which can give a WHP for that particular condition. Calculating acceleration losses is another thing altogether. The more 'stuff' you have to accelerate, (extra diff, transfer box, driveshafts, etc.), the greater the losses. The harder the pull, the more friction, windage, etc.

[Ajs_435d]

Originally Posted by HighlandPete

When we talk about wheel horse power vs. engine horse power, are we calculating it under acceleration, or at a steady state? An engine at peak power, (or any other power output for that matter) holding a theoretical road speed, has got 'x' amount of drivetrain losses, which can give a WHP for that particular condition. Calculating acceleration losses is another thing altogether. The more 'stuff' you have to accelerate, (extra diff, transfer box, driveshafts, etc.), the greater the losses. The harder the pull, the more friction, windage, etc.

The two will produce differing figures, but the purpose of this thread in the same gear from low rpm to redline thus acceleration. The issue here is friction.

Enjoying this thread makes my lunch break more interesting haha.

[HighlandPete]

Originally Posted by Ajs_435d

The two will produce differing figures, but the purpose of this thread in the same gear from low rpm to redline thus acceleration. The issue here is friction.

Enjoying this thread makes my lunch break more interesting haha.

Gets the grey cells working.

What I see in the context of real world driving, and many have commented on this over the years, the 35d engines can appear a little underwhelming. Stretch the working envelope and the 35d engines show more of a performance difference. All made more complex by BMW going xDrive 'only' on the 35d. Blunted the typical UK 'real world' performance differences, compared to the 330d RWD.

As to drivetrain losses, all kinds of numbers are banded about. As you know, even dyno testing is not an exact science. Only a separate engine dyno (as you mention) can really get a baseline figure, to start any meaningful calculations. Even then it is limited to one set of conditions, would take a lot of specific testing to generate/plot graphs over a range of operating conditions.

[Dr Forinor]

Definitely an interesting topic. Thanks for the knowledgeable inputs.

[Hooded]

Originally Posted by JD6

Despite liking the 30d, I'm surprised by the suggestion on this thread that the performance difference is narrow. It doesn't feel like that.

ACS indicate that the 330d sDrive takes 14.9 seconds from 80-180km/h versus 11.8 seconds for the 335d. Quite a difference. Admittedly this includes a small element over 100mph

http://preisliste.ac-schnitzer.de/ac...01&ID_NR=11645
http://preisliste.ac-schnitzer.de/ac...00&ID_NR=10315

Where this has actual average varified tested figures as only one second difference 80-180

http://www.zeperfs.com/en/duel5992-6195.htm

330d sdrive 13.6
335d xdrive 12.6

[JD6]

Originally Posted by Hooded

Where this has actual average varified tested figures as only one second difference 80-180

http://www.zeperfs.com/en/duel5992-6195.htm

330d sdrive 13.6
335d xdrive 12.6

I thought ACS used real figures too. That's quite a difference Lorcan ?

[Hooded]

Originally Posted by JD6

I thought ACS used real figures too. That's quite a difference Lorcan ?

I'm not sure where ACS get their standard figures from, maybe BMW quoted figures?

The average varified performance figures on the link I provided are ..
* Measures (at real speed) by the following car magazines : Auto Motor & Sport, Sport Auto

[Lorcan]

Originally Posted by JD6

I thought ACS used real figures too. That's quite a difference Lorcan ?

Our figures are from our own testing. They are what they are...

[JustChris]

Not sure if this has been added but back in the day when I chose 335d BMW support made it cheaper per month on PCP than a 330D so that was that.