50i a bit laggy?
 

interested in new 50i owners views ... there's a few people now I've heard from who are saying it can have a lag delay off the line ....any other feedback ?

If it's anything like the X6 50i, there's no lag issue. The new X5 also has the 8-speeder with a lower first gear, I presume.

If you are really worried, go drive a X6 50i at a dealer. There's a few second-handers getting about.

:iagree:

No lag here :D

Don't notice any lag on mine. Very smooth, even my wife commented on how smooth the shifting feels compared to our old X5 (06 4.4i). Definitely pulls hard between 3-4k rpm.

Any car with turbos has some kind of lag off the line. I'm used to driving naturally aspirated engines with great throttle response and I really feel any lag when it's there.

Manufacturers have gotten much better over the years making it less and less noticeable. If this were a real issue, BMW could add a small electric motor to spin the turbos for a better launch but it's just not an issue in practice.

Keep in mind on the 50i that even without the turbos, this is a great 4.4 liter V8. I think the only reason it's noticeable is that things get really crazy when the turbos spool up. :)

I view it as a completely appropriate compromise - you get the increase in power/torque and better mileage with a little lag off the line.

As usual, test drive before you buy.

You say the lag is noticeable but have you actually driven a 50i?

huh??? you obviously have not driven either the N54 or the TT 4.4.

Exactly what I was thinking. My N54 doesn't exhibit any lag. I have been driving (with a license) for 34 years, and have driven many turbocharged vehicles. Some had lag. That is now old news.

Yep, no lag with the N54 nor with the 50i.

ok ...thanks everyone ..perhaps it just a relative thing based on each persons experience. .. have driven the 135i and 335i and noticed some degree of lag ... but once again that's just me ... on the X5 35d I do notice some lag ... not really from standing start because you can overcome that with a little bit of rev-lifting before launch ...more when your crawling and then punch it ..it just takes a split second for the smaller turbo to wake up and kick ... a bit less noticable in DS mode ..but still there ...wonder if the new twinscroll single turbo has sorted that problem out ?

If you think the 335i has lag then you must be an impossibly hard marker. What do you want? A supercharged 7-litre V8 in a Lotus Elise with extra low gearing?

I use to tune turbo's when I owned subaru's ... (WRX STI etc) ... when you tune a car like that you iron out lag pretty quickly.

I have a friend who did a remap on his 335i and it is a definite improvement ..I think the problem is that like most mass manufactured cars these days (yes, even BMW;s) the engineers try to strike a balance in terms of smooth performance / economy ... and in some cases its even worse as they apply a broad-brush factory tune to all models that's just plain sub-optimal ... (except M's of course - they get special attention)

If you can tune an STi to have no lag then you are a genius... I didn't realise you are a car engineer. All the WRXs I have driven, STis included, are lag city compared to the 35i.

APS kit ... no lag. I'm not an engineer .. but my father is. We use to track it. bog standards STI is definately laggy ..no denying that.... in fact WRX standard feels better (until you hit a corner) ... subaru lost thier way over the last few years ..so ditched them ...

Track driving is a completely different thing to stop-start road driving.

What some may be experiencing is not "turbo lag" but second gear starts due to the way the engineers programmed the car for fuel economy and the new 8-speed transmission. As stated in the review entitled 10 Things You Should Know About the 2011 BMW X5... "Our only complaint involves the new transmission. When in Drive, it is programmed to start in second gear, which can lead to some sluggish launches."

Maybe this explains it? I have not test driven a 2011 X5 50i so I have no first hand experience.

laggy in comparison to what?

I would like to give that a spin:D Anyways I haven't driven the 2011 x5 but I did get a chance to drive the 4.4 tt in the 2011 550i and I did not notice any lag whatsoever. In fact the low end power is nothing short of spectacular.

I suppose the only way for me to really know is to test drive new models ..they should land demo's here in few weeks ..I've told my dealer to reserve some slots ...

I drove the 50i, 35d, 35i and my own naturally aspirated 4.4i the same day - http://www.xoutpost.com/bmw-sav-foru...ives-long.html.

I noticed some hesitation/lag off the line in the 50i. It wasn't a big deal but something didn't feel right. There are a bunch of things that could be at fault if it wasn't the turboed engine - it's possible I started in 2nd (though pretty sure I was in DS), the car only had a few miles on it and those 20" wheels didn't help.

This is only from a 30 minute test drive so I'll have to take the word of folks that have driven it for longer but as always, I recommend everyone decide for themselves with their own test drives rather than taking the word of anyone on message boards.

anzer, one thing I should point out - it's one thing to say there is a little lag off the line. Even with the minimal lag I experienced (whatever the reason), I would certainly not describe the 50i as "laggy" which implies that lag is an issue with the car which it certainly isn't. Whether or not there is lag, it is nothing to be concerned about.

BTW, the only other mention to lag I've seen was from a X6 50i owner in response to my test drive post:
http://www.xoutpost.com/739989-post4.html

Exactly!

The 50i has close to 20 percent more power and torque at 1000 rpm than the 48i and the power/torque differential between the two increases rapidly from there.

Turbo Lag is the leg warmers of the 201xs, stop being ignorant! All my vehicles are turbocharged.

I'm not getting your drift?

Fraser, what I mean is that people use the term "turbo lag" a lot but usually with very little real world knowledge. If you're driving a 1970s Porsche 930 then yes, you're going to experience turbo lag. With old school technology turbochargers, 6:1 compression etc the experience in transitioning onto boost will be radical. The "light switch" transition that people fear.

However in 2010 with a BMW OEM turbo system on a large capacity V8 multivalve engine with latest technology turbochargers .. really you're not going to experience the same issues. The turbochargers are ball bearing and they spin up so much faster, the exhaust gas volume generated by a large capacity multivalve V8 with variable valve timing is a different world to an old school flat 6 plus the ECUs now are vasstly superior.

I don't believe tubo lag is an issue on this vehicle. :-)

Nor do I. Nor on the 35i. These are both seamlessly tractive engines that are a driving delight. Perhaps not so good at the bowser if you've put your boot in, especially with the 50i and in heavy vehicle like the X. 335i is sublime and a great poor-man's M3.

For me the lag I'm really talking about is when you are cruising at about 30km/h down suburban street, slow for a speed bump at about 20 ..then try to accelerate briskly on the other side of the bump ...but ... catch the turbo sleeping and it takes too long to spool .... have also had the same problem cruising up to give way signs (for example) then flooring to get across traffic and slight delay (enough to be dangerous at times) ....

I suspect some of this has to do with the 4WD getting its act together? anyway ..there's flat spots that shit me ...especially when the 35d is suppose to have most of it torque spent by 2000 rpm ... but when you sit there waiting it certainly doesnt feel like that ... I drive in DS now to keep revs a little higher ..that seems to help a fair bit .....

In terms of 50i I read a motoring review that mentioned a little lag ..but once again this could be more about the '2nd gear start' that some are referring to on the new 8 speed box ?

When the 50i, 40d and 35i arrive I'll go and drive then using these sort of real-world driving scenarios - I'm sure I won't be disappointed ...but everyone has different expectations so no right or wrong answer I suppose ...just personal preferences ... good discussion though ..thanks for inputs

Fraser - went for 200km drive today (resetting BC) and avg was at 10.2 !! that's more like it (and I was pushing it here and there in the 110km zones) ... took your advice and headed for some hills to mix up the run-in terrain a little ... no doubt when school runs start again tomorrow I'll be heading back to 16 ;(

I think you're talking about an automatic gearbox and real world physics with a 2500 kgs vehicle rather than turbo lag!

The auto and weight don't help, agree ..but there's lag in my view that occassionaly catches the 35d out ... I often wonder if the balancing of the TT on the 35d is not well tuned from factory ..I think the 40d has gone single turbo with twinscroll (like 740d) ..so should be interesting to compare ...same with 35i which has gone N55

I thought we are talking about 50i, and to a lesser extent 35i. You can't talk about turbo diesels and turbo petrols in the same breath. Completely different. 40d is still twin, sequential turbos, like the 35d. The main diff is that the 40d's small turbo is now variable geometry whereas with the 35d the small turbo is fixed geometry.

I'm using my own 35d experience to help benchmark what I may expect from 50i .. I'm not particalary impressed with the 35d in terms of around town performance .. hence my interest in the 50i (and even 35i) ... if the 40d's turbo 'shape change' has fixed things then that could be of interest also ..just keeping options open ...

and I don't see the harm in comparing petrols to diesels when it comes to performance (both fuel usage and speed related) ..not all of us just want to tow caravans and boats ...

The point with diesels vs petrols is that an amto three-litre diesel in something like a X5 wouldn't have the power to get out of its own way whereas an atmo 3.0-litre petrol can be more than acceptable. When the last time you drove an atmo diesel?

Now that I have around 30 minutes in the 50 under the belt ;) I can say for certain that If I didnt know that this was a turbo charged set up I would not guess that was by just driving it. There is no hit of lag at all. Power is available at any rpm and at any speed. Its trully a blast to drive and much more technologically advanced and comfortable then my 911....

Being that I have yet to see a 2nd 2011 on the road in my neck of the woods Im not surprised at being asked all sorts of questions about it at stop lights and at my kids school.