funkatation

My local dealer had a few TDI's come in so I went to test drive one. I noticed the engine had lots of power, but it took longer than I'm used to for it to kick in, then it really kicked in! Seems like it would take a little to get used to. Anyone else experience this? Curious how this would compare to the Biturbo in the GLK, which has less power, but it comes on sooner. Anyone drive both?

Mark P

What kind of car/engine is your reference?

Jacket

We just picked up our Q7 TDI a month ago and both my wife and me observed that same behavior. It seems as though the drive by wire system is oddly tuned if you are coming from another car. From a stop, it initially goes no where, and then when you give it a bit more gas it grabs and goes pretty dramatically.

I suspect driving habits will change and we'll get used to it, and I also think it drives more "normal" in S-mode, so if you go back for another drive try the transmission in Sport and see if you like it better.

idale

Didn't notice any issues at all with lag on my test drive, but granted I didn't even bother with D (what's the point, lol). I also wasn't looking to peel out from a stop, so didn't try and verify the 0-60 time or anything, just working on "normal" driving and didn't notice any undue hesitation.

larryV

Lag is just the nature of any turbocharged engine, gas or diesel, but it is typically more pronounced in a turbodiesel due to the higher boost pressures, the higher compression, and the simple fact that it doesn't rely on spark plugs for ignition like a gas engine does.

When I drove home my first TDI vehicle (a Touareg) after years of driving nothing but gas-engined cars, it took a while to get used to the delay between accelerator inputs to forward thrust. Probably a week or so. After a while, I grew to like it. Mostly because of the nice huge kick in pants effect of the torque rushing in without the engine having to rev too much. It was a nice rubberband effect when you mash the go pedal and almost nothing happens during the initial fraction of a second, but then you know you're about to get hit by a massive surge of torque shortly after. A fun feeling no doubt. So much so that when I got back in a gas vehicle, I missed the effect. I miss it now. But it's apples to oranges. TDI = massive low end torque but laggy and no top end, gas = great throttle response but anemic (relatively speaking) until rpms build. Too bad we can't have both: big low-rpm rush of torque AND instantaneous throttle response. Well, I guess we almost can, but a Tesla Model S or similar performance electric vehicle isn't for everyone

macwm

My wife and I have been driving our remarkable TDI for almost 3 weeks and 850 miles, and have not noticed any of the described symptoms. Of course we are not mashing the pedal from a dead stop. That's not how to drive a turbo; it just does not respond at any speed. Actually, the throttle response seems very similar to our '11 Q5 2.0T. My friend purchased a '13 BMW 528 xi, and complained that his car didn't respond to throttle input in the same way. After a little education on how to drive and accelerate, he's much happier. The start / stop system takes a little getting used to. Just for fun, I've tried to out race the system by moving my foot as quickly as possible from the brake to the accelerator pedal. Even with that scenario, the TDI exhibits no noticeable lag. I guess it's how you drive the vehicle. We love this car!

Q5 Bob

I don't have a diesel, but have learned to be smoother on the throttle with the 2.0t to avoid the peakiness inherent with this small boosted engine,

Haku

From a point of reference regarding the Q5 diesel I state that I've been driving the 2013 VW Passat 2.0 diesel for the past year as well having owned a Q7 diesel prior to that.

I too test drove the Q5 diesel last week and was surprised at the length of lag. Of course one expects it in a turbo but I found it disturbingly long. Its odd but I didn't notice it so much on my Q7 and even less on the Passat. I for one love the torque on diesels and was leaning towards it on the Q5 but ended up going for the 2.0

Back to your specific issue re comparison to the Mercedes. Whilst not a GLK I test drove a 250 with a turbo and gas engine and absolutely hated it! The turbo lag on the low cc non high performance engines is imo so bad (at times a 2 sec delay before anything happens) that its almost dangerous! I was happy to head right back to Audi!

I do agree overall with other posters that driving styles of course need to be considered and maybe changed but when power is needed to get out of a jam long delays can be awkward.

Parsec

You can have both with a big engine, so that leaves out most European and Japanese cars. Think Camaro ZL1 or Mustang Shelby GT500.

tomaszp72

3.0T is basically that. Low torque with instant acceleration, no trubo lag.