Z4 SDrive 30i - why the old engine?
Discussion
Just realised today that the Z4 SDrive30i (And 23i, infact) doesn't use the N53 engine introduced 4 years ago. Infact it's still using the older N52 engine.
This means that it's nothing like as economical nor does it have the low CO2 engines of the newer engine.
Does anyone know why this is? It does seem a bit strange - the N53 replaced the N52 in the E60 5 Series and E90/91/92/93 way back in 2007 and brought with it significant reductions in CO2 emissions and a big increase in fuel economy.
I understand that the N53 is not offered outside of Europe due to fuel quality issues, is it as simple as the fact that given that such a high proportion of Z4 production ends up in the USA it simply isnt cost effective to offer the newer engine?
Does seem quite bizarre, and makes any Z4 that isn't a 35i pointless as the 30i and 23i are barely any more economical than the 35i, so why bother. Contrast this to 330i v 335i where the combined consumption figure on a 2008 330i is almost 10mpg better than the 335i due to the newer engine.
In this age of obsession with CO2 and high fuel prices it does seem odd not to offer the far more frugal engine and instead stick with a much older one.
This means that it's nothing like as economical nor does it have the low CO2 engines of the newer engine.
Does anyone know why this is? It does seem a bit strange - the N53 replaced the N52 in the E60 5 Series and E90/91/92/93 way back in 2007 and brought with it significant reductions in CO2 emissions and a big increase in fuel economy.
I understand that the N53 is not offered outside of Europe due to fuel quality issues, is it as simple as the fact that given that such a high proportion of Z4 production ends up in the USA it simply isnt cost effective to offer the newer engine?
Does seem quite bizarre, and makes any Z4 that isn't a 35i pointless as the 30i and 23i are barely any more economical than the 35i, so why bother. Contrast this to 330i v 335i where the combined consumption figure on a 2008 330i is almost 10mpg better than the 335i due to the newer engine.
In this age of obsession with CO2 and high fuel prices it does seem odd not to offer the far more frugal engine and instead stick with a much older one.
The new BMW E89 Z4 is built in Regenburg, West Germany where its predecessor the series 1 Z4 was built in the Spartanburg, South Carolina. The N52 in my opinion is the more advanced engine than the N54, for example it has a lighter magnesium-aluminium block and valvetronic which is missing on the forced induction N54 engine. But most important is the fact that the N52 engine is a port injection engine and NOT A DIRECT ENGINE which all seem to have carbon build up problems in the inlet tracts. This carbon build up ultimately effects performance and efficiency over time and the claimed new figures become diminished as mileage increases. Also N52 does not use the HPFP which has been problematic on the N54.
Edited by piper on Thursday 26th May 13:42
piper said:
The N52 in my opinion is the more advanced engine than the N54
Yet emits more CO2 and uses more fuel?The N53 is a way of having a proper engine without needing to buy a diesel with pump prices as high as they are.
The carbon thing I have heard before, though - presumably this is not covered by warranty either?
Fox- said:
The N53 is a way of having a proper engine without needing to buy a diesel with pump prices as high as they are.
Really? 33.2mpg vs. 38.9 is hardly a staggering difference - your driving style will be FAR more influential to your consumption than the 5mpg claimed difference (extra urban this difference goes down to a claimed 2mpg).Either way, neither will get close to a diesel for outright economy
And an extra £35/year on tax for the N52... hardly a deal breaker!
Fox- said:
Does seem quite bizarre, and makes any Z4 that isn't a 35i pointless as the 30i and 23i are barely any more economical than the 35i, so why bother. Contrast this to 330i v 335i where the combined consumption figure on a 2008 330i is almost 10mpg better than the 335i due to the newer engine.
But look at it the other way round, with the 30i you get the same fuel consumption but have 60 odd more horse to play with - it's a no brainer! It's the same with the 325i vs 330i (both have N53's) - the 330i has the same economy but with more power! If you want outright economy why go for a 3-litre engine? But good question, I don't know why they wouldn't use their latest non-turbo variant in the 3 series and not Z4?
Edited by navier_stokes on Thursday 26th May 20:08
navier_stokes said:
But look at it the other way round, with the 30i you get the same fuel consumption but have 60 odd more horse to play with - it's a no brainer!
But in the Z4, you may as well go with the 35i and have 90bhp more to play with 
[quote] If you want outright economy why go for a 3-litre engine?
The N53 is a stratifed DI engine (runs a lean overall mixture at part load). It's applications are pretty much limited to the European market 3 and 5-Series (and old E6x 6-Series). This is because the NOx trap necessary to meet NOx emission limits in Europe requires very low sulphur fuel to avoid it being deactivated, thus ruling it out of a lot of markets where that fuel isn't available. However, even where the fuel is available the tailpipe NOx levels may still be too high for the emissions standards there (e.g. US & Canada). To meet these more stringent regs. you might need an alternative NOx reducing technology such as Urea SCR (as fitted to US diesels), but this all costs and to date no one has done this on a petrol engine commercially - at least to my knowledge. The new M276 3.5 V6 from Mercedes is stratfied DI in Europe (in C/E/CLS and, I think S-Class), but where it is available in the US it operates in homogenous mode only.
Even in Europe, the benefits of the stratified DI engines in applications where they would need to operate at higher loads more often (and therefore not be in stratfied mode) are reduced to the extent that it's not worth the trip. Hence, them not being used in the heavier SUVs. As regards Z4, technically it would be beneficial for EU cars to use N53, but with it being a low volume product it's not worth it to engineer different powertrains for different markets. For the 3 & 5-Series it was because of their higher volumes and because taxation in Germany heavily favours fuel efficient petrol engined cars because diesels pay a hefty penalty.
Improved fuel economy for the Z4 will come with the new (homegenous) DI turbo 2.0 I4 engine, which will replace at least some of the I6 N/A derivatives - I believe the 2.0T will be sDrive28i at launch. It's probably reasonable to expect stop-start at some point too, but probably not for all markets. New Merc SLK has stop-start in Europe and it's also forecast for next gen. Boxster.
Even in Europe, the benefits of the stratified DI engines in applications where they would need to operate at higher loads more often (and therefore not be in stratfied mode) are reduced to the extent that it's not worth the trip. Hence, them not being used in the heavier SUVs. As regards Z4, technically it would be beneficial for EU cars to use N53, but with it being a low volume product it's not worth it to engineer different powertrains for different markets. For the 3 & 5-Series it was because of their higher volumes and because taxation in Germany heavily favours fuel efficient petrol engined cars because diesels pay a hefty penalty.
Improved fuel economy for the Z4 will come with the new (homegenous) DI turbo 2.0 I4 engine, which will replace at least some of the I6 N/A derivatives - I believe the 2.0T will be sDrive28i at launch. It's probably reasonable to expect stop-start at some point too, but probably not for all markets. New Merc SLK has stop-start in Europe and it's also forecast for next gen. Boxster.
Sorry, I've been away. No, the N54 is not stratified. None of the DI turbo BMW engines are - V12, the V8s (M and mainstream) , both I6s and the new I4 are all homogenous DI. Don't know where the new I4 will be sold (it is going to the US), but the other engines are sold in most markets globally.
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