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Originally Posted by AMG Power Not true. The below pics are of gear ratios from the Superb 170 bhp and Octavia 150 bhp versions. The gear ratios shown for the Octavia are different from that sold in India. VW have different gear ratios across the globe. In the pic above, the 170 bhp makes 120 kmph at 2000 rpm and the Octavia makes 120 kmph at 2300 rpm. |
Hello,
I did make a mention of 'between a particular vehicle model' and 'particular transmission type' in my responses. If we are to compare the stated/claimed FE of 2.0TDI engines in varying states of tune, we have to normalize them for vehicle weight, gear ratio, aerodynamics of a vehicle model, transmission type /associated losses, FE test-cycle, fuel quality etc and more, which I believe you too would agree to.
This is done easier by comparing the same generation of 2.0TDI engine in varying states of tunes and which uses identical transmission type, in the same vehicle. i.e to compare FE/CO2 ratings between say a Mk2 Octavia 6-speed DSG in its 140PS vs 170PS variant, or a Mk3 Superb 6-speed DSG in its 150PS vs 190PS etc. Currently we don't have such options for models launched in India, but EU have them.
Few points I would like to highlight:
- In the example, you are comparing between two different vehicle models: Octavia vs Superb and not from their same generation either. They do have different gear ratios, weights, drag coefficients etc.
- Yes, vehicles do have different gear ratios in different markets. I know that my Polo in India is geared shorter than the ones in EU, even while making more power/torque than them. To be honest I don't know whether cars like Octavia/Superb/Jetta etc also do since they are CKD units, and if it is worth for VAG to have different transmission parts bin for a small market like ours.
- But then again if we are to compare FE using ARAI results (kmpl) or CO2 ratings (g/km) obtained in European test cycle (NEDC), we can conisder only vehicle sold in the same markets as they are tested with different fuel grades as well as test-cycles.
- Among 2.0TDI engines in OP's post, there are two different series/generations. The 110PS/140PS/170PS are from the EA189 series (diesel-gate). The 150PS/190PS variants are from a newer EA288 series which went into MQB based cars (de-tuned to 143PS/177PS respectively in India). So comparing between 150PS vs 170PS 2.0TDI variant means you are likely comparing two different engines all together.
- If you are comparing between 150PS Octavia and 170PS Superb, then you are comparing two significantly different generations of engine and vehicles; to be precise EA288 2.0TDI in a Octavia Mk3 (MQB) and the older EA189 2.0TDI from a Superb Mk2. Different chassis platforms, vehicle generations, the older generation being heavier by odd 60-100kg between corresponding models. So yes they indeed have different gear ratios, no surprises.
- You can look up CO2 ratings of 140PS/170PS variants of Superb Mk2 (both 6-speed MT or 6-speed DSG), or 150PS/190PS variants of Superb Mk3 (again both 6-speed DSG/6-speed MT) and find that the CO2 ratings are pretty much the same.
- Gear ratio data via official VAG documentation is hard to come up. Only few catalogs/brochures have them, for example in the Seat Ateca (a Tiguan Mk2 equivalent).
- I presume the data is from 'http://www.cars-data.com' in these screenshots. But they occasionally have mistakes in them
. You can look at their data provided against compression ratio / brake disc dia etc for eg.
Coming back to question of FE ratings of 2.0TDI engines: they are indeed similar between comparable 150PS vs 190PS applications or 140PS vs 170PS ones, owing to the limitations of test cycles (same acceleration rates irrespective of vehicle's capability, peak power/torque not utilized), and a highly similar base engine, rather than different gear ratios (which many time tend to remain the same).
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Originally Posted by AMG Power Here's an extract from the tech specs of the TDI CR with 110/140/170 states of tune for the Octavia. As you will notice, the 110 and the 140 have the same gear ratios but the 170 has different gear ratios. |
Quite interesting. Could you please share the link to the same? Always something out there to correct and learn
However, going by the data you shared, you will notice that that 170PS is paired with shorter ratios than 140PS variant, isn't it counter-intuitive then and not as you expected? Calculating with a 205/55 R16 tyre (approx 632mm of rolling diameter), the data of gear ratio in the screenshot yield that 120kmph comes up at for 170PS: 2222rpm (6th gear) & 2640rpm (5th gear), and for the 140PS: 1990rpm (6th gear) & 2380 rpm(5th gear).
P.S: I saw your second response after typing mine for the first. But I will still keep them as it may help other readers to be in context, I understand you already quite are.
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Originally Posted by Jeroen Thanks very much for putting this table together. |
Graag gedaan. Back home in India with troublesome after sales support of VW/Skoda, you end up reading and researching more than required.
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Coming back to our earlier discussion, does suggest that parts are ‘over-engineered’ to cope with these difference. Which suggests to me that the cost advantages of overall standardisation are larger then trying to produce each and every part to an individual specification per engine version.
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I too assume that they are over-engineered. It also means that someone picking up a used variant of VAG 110PS 2.0TDI (say a Laura MT or Yet 4x2) has lots of room to extract more the engine, if he chooses to. Another engine that comes to my mind with such a broad power application in the 2.2L four pot diesel from Merc, which was seen in approx 110/200PS and 250Nm/ 500NMmapplications. However, I am not familiar with its generations or iterations or part catalogues.
P.S: I am staying odd 100-150 south (I presume) of your location and hope you are enjoying the sun. Nice to meet you here in this thread.
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