Mark P

Excuse the dramatic title, but I was quite happily surprised with the 8th gear acceleration results I captured...

Recently I logged both a Q5 3.0T and my TDI on the same strip of flat, straight road, in comparable temperature, etc. Every test I did 2 passes in each car to ensure results were repeatable.

I did a handful of other comparisons (ie 0-60) which were all much closer than this one. I'll post about all of the results later, but wanted to get this one up now

This comparison was for the cars to be in M8, cruise control at 60mph and fully accelerate without kickdown, to 80 mph.

As you can see, the 3.0T makes it to 80 in an average of 15.1 seconds, while the TDI only takes 9.4 seconds!



* I actually computed to 79mph since one of the runs didn't make it to 80. 79 was the highest common across all runs.

You can also note from the RPM graph data how similar the gearing is. They both have the same tranny, but the 3.0T has a 3.204 final drive, while the TDI has a 3.076. At 60mph, this results in 1484 RPM for 3.0T and 1425 RPM for TDI, hardly seems worth there being a different part. The largest difference would be about 175 RPMs at the highest RPM they have in common (~4500).

Bottom line, this resulting RPM range of 1500-2000 RPMs clearly favored the torque of the TDI

UPDATE: Here's the link to the post with all 4 comparisons:
https://www.audiworld.com/forums/sho...php?p=24512811

Coolieman1220

And people called me crazy when I said this in another thread. (though i was saying the sq5 which has a much larger gearing advantage)

Thats the beauty of a diesel.

koobah

The 3.0T you used has been handicapped by Audi who decided to detune it to 270hp. Still a very impressive result nonetheless. If only Audi made the diesel available in US spec SQ5...

spijun

True, but the biggest advantage a diesel engine powerful torque which in this case is higher by 45% compared to the petrol engine

3.0TFSI 400Nm (295 lb-ft)
3.0TDI 580Nm (428 lb-ft)

Rlk1

+1
Hoping that we will see the TDI by the next generation SQ5 for the 2017 model year, then I am all in. I would think it would be since the Q5 has the TDI now.

NABS4

Wow, talk about "cherry-picking" data. Your test is in the proverbial "wheel house" of diesel strength. How does the TDI pull over 5000 rpm, or more specifically over 4750 rpm?

BlackSVT

I was thinking the same thing.

I do have to say though, Audi's power de-tuning approach on the straight 3.0T (as opposed to the SQ5 variant) makes it feel a little breathless and diesel-like as well above ~4,500.

NABS4

Yes, Audi even has the S4 tuned this way. Revo/APR can fix this trait.

Mark P

I think I made both of those points clear in my post. Not trying to hide that by any means. I have 3 other comparisons I'll post as well. In all of those (or at least 2.5), the 3.0T outperformed the TDI. However the differences were much more subtle in comparison to this one, which led me to post this first. And because I have a TDI :P

I did not chose this test based on RPM (to favor the TDI) - I chose it based on a reasonable speed range (60-80mph) consistent with what some magazines test (I think 50-70) in top gear. In general, I'm not a fan of a top gear test as it favors the guy with the crappier-economy-geared vehicle. In this case, they have the same tranny and near identical final drives, so that wasn't such an issue. Also, this test came in part out of the video that was posted that claimed the TDI was "flat footed" on highway accel, for which there was some inference or we created one in that thread which tied to top gear.

Here's that post/thread:
https://www.audiworld.com/forums/sho...php?p=24504521

So yes I would have expected the TDI to outperform the 3.0T in this test, but after having driven both of them daily, I wasn't expecting the difference to be this great. All around, they seemed to perform quite similarly.

The other tests I'll post are (1-3):

1.) 0-100 in "S", ESP off, foot to floor (w/kickdown)
> Scenario: Fastest off the line (eg 0-60)

2.) 45-100 in "S", full throttle (w kickdown)
> Scenario: Similar to a common B5S4 testing range. Fastest possible from that starting point. Street-racer type comparison.

3.) 60-100 in "D", full throttle (w/o kickdown)
> Scenario: Highway passing; quickest in civilized (no "S" or kickdown) manner (ie wife/family in car)

4.) 60-80 in "M8", full throttle (w/o kickdown)
> Scenario: Top gear comparison.

Each car gets to pick their own gears for those tests so nobody can complain

josedebardi

I find even in D if I floor it w/o KD it still drops a lot of cogs... The KD button is almost pointless as far as I can work out!