Fuel economy. Passat Vs Superb.

[Kiwibacon]

Ok passat cc 2.0 tdi 170 bluemotion tech.

Cruising at 63 mph speedo on a flatish road over 10 mile gave 59mpg indicated. It overeads slightly so probably about 56mph.

Was at 1700 rpm

Thank you kindly, that's pretty much 5 l/100km. Manual or DSG?

[dec76]

Skoda Superb Elegance Estate 170 TDi DSG over 514km at 100-110km/h read a brim to brim of 4.9L/100km. This was done in 25 degree centigrade over the last weekend. The MFD stated 4.7L/100km.

Hope this helps.

[Kiwibacon]

Skoda Superb Elegance Estate 170 TDi DSG over 514km at 100-110km/h read a brim to brim of 4.9L/100km. This was done in 25 degree centigrade over the last weekend. The MFD stated 4.7L/100km.

Hope this helps.

Yes thank you, that does help. Do you remember what rpm it turns at 100?

Edited 8 May, 2012 by Kiwibacon

[simonsheil]

Manual

[Coops]

2.0 CR 140 - 100 km/h: 1600 rpm, approx 65-70 mpg

Done on cruise in 6th, manual gearbox.

HTH

Sent from my BlackBerry 9300 using Tapatalk

[Danny 57]

If you apply more right foot, then you end up going faster than the 100km/h I'm asking about. No?

I'm still hoping someone can supply some figures for me.

Yes you would if no one else was on the road but that is never the case even on motorways (certainly Britain). There is the anticipation of waiting for someone to pass to be able to overtake a slower vehicle, rush hour (most of the day in some areas) traffic that causes you to slow down then speed up ect. This is what I meant. :yes:

[Kiwibacon]

2.0 CR 140 - 100 km/h: 1600 rpm, approx 65-70 mpg

Done on cruise in 6th, manual gearbox.

HTH

Sent from my BlackBerry 9300 using Tapatalk

Thank you. It's good to see the rpm for a manual. The only cars available in this country to test drive are DSG.

Edited 8 May, 2012 by Kiwibacon

[Kiwibacon]

Yes you would if no one else was on the road but that is never the case even on motorways (certainly Britain). There is the anticipation of waiting for someone to pass to be able to overtake a slower vehicle, rush hour (most of the day in some areas) traffic that causes you to slow down then speed up ect. This is what I meant. :yes:

If you are only stabbing and the throttle and coasting, then it doesn't impact fuel economy. Done smoothly it can even increase it slightly (that's how the hypermilers work). This is because your engine at high load is a little more efficient than at cruise. Accelerating at high load and then coasting in between can add to your mpg if done right. But it's a much smaller gain on diesel engines than petrol.

It's very similar to driving in rolling hill country. If the gradients are good to allow climibing in top gear and coasting without braking I can gain fuel economy. But such roads can be rare.

If you are on the accelerator, then brakes, then yes your economy will turn to poo. But any braking does that. All the energy used to wear out your brakes comes from your fuel tank.

Edited 8 May, 2012 by Kiwibacon

[ddyer79]

One thing I did notice today is that the Passat has a much larger fuel tank 85 versus 67 litres which is a benefit in terms of range but all adds to the weigh to pull around when full. Fuel consumption tests are done with very little fuel on board, air con off and in a specific ambient temperature, things,that along with weight of passengers, extras and luggage combine to make factory consumption figures meaningless in the real world.

[Alvaro]

I think fuel tanks are 70 in the Passat and 60 in the Superb.

[Kiwibacon]

I have finally found the skoda gearing. I decided to go find a german site and viola.

http://www.skoda.de/...p?e=348-9-7-2-2

The results are (drum-roll please) for 100km/h cruise.

125kw 4x4 manual ~1911rpm

125kw 4x2 manual ~1798rpm

103kw 4x2 manual ~1612rpm

103kw 4x2 manual greenline - same as non-greenline.

103kw DSG ~ 1874rpm (same for 4x2 and 4x4).

I think Skoda have geared the 125kw cars lower so they feel like they have more top gear pulling power. Since they only have ~10% more torque (350Nm vs 320Nm) they geared them down by another 10% so it feels like they have around 20% more power available at 100km/h in top gear.

So far this is explaining the fuel consumption stats quite nicely. Namely why the 125kw 2wd cars use more fuel than the 103kw cars in the same test when accelerating at the same speed. It's simply because they are turning faster and losing more to internal friction.

Edited 16 May, 2012 by Kiwibacon

[sk8tergirl]

Hi Kiwibacon,

Interesting figures. I've got the 125kw /170ps manual & agree with the 1800rpm (I can't confirm its 1798 though LOL).

However, if both cars have peak power at the same rpm (ie. 4200) and assuming (and I guess this is the critical assumption) that both run out of puff at the same time (ie. in the rpm range) then would that not mean that the 103kw will have a higher top end speed??? Or at least a virtually identical top speed... but obviously it doesn't, there's about 10mph in it.

It does seem odd to me that they are geared that differently but it seems that its all to make the car seem faster at slower speeds (or lower in the rev range).

I'm no mechanic but I have a sneaky feeling from some of your posts you'll be able to shed a little more light on this... :think:

Thanks

Stef

Edited 16 May, 2012 by sk8tergirl

[Kiwibacon]

Top speed is an interesting one, it's where the power you've got and the power you need meet. It does mean that if you get enough power to hit the rev limiter, that the 103kw box is going to let you go faster than the 125.

I wonder what the response would be to ordering the 125kw car with different gear ratios?

[Kiwibacon]

I've been trolling (fishing term, not internet trolling) German sites and I found interesting threads on fuel economy. It looks like the 4motion passat sits on the wrong side of 40mpg most of the time:

http://translate.goo...vAKmHAmpMg7tZSg

To get under 5.5 litres/100km they are talking driving at 90km/h.

It appears the passat is getting the same real world figures as the superb. Why the superb is testing differently is another matter. How recent are fuel economy tests? Is there any mandate for car companies to update them?

Edited 17 May, 2012 by Kiwibacon

[Phil_P]

I have finally found the skoda gearing. I decided to go find a german site and viola.

http://www.skoda.de/...p?e=348-9-7-2-2

The results are (drum-roll please) for 100km/h cruise.

125kw 4x4 manual ~1911rpm

125kw 4x2 manual ~1798rpm

103kw 4x2 manual ~1612rpm

103kw 4x2 manual greenline - same as non-greenline.

103kw DSG ~ 1874rpm (same for 4x2 and 4x4).

Do you have the 100km/h cruise figures for the 1.6TDI (77kW) please (the new GreenLine)?

For reference, my 2.0TDI (110PS/81kW) 5-speed manual Passat cruises at 100km/h at ~1950rpm

[Kiwibacon]

Do you have the 100km/h cruise figures for the 1.6TDI (77kW) please (the new GreenLine)?

For reference, my 2.0TDI (110PS/81kW) 5-speed manual Passat cruises at 100km/h at ~1950rpm

From the figures on the same page I'm getting 1864rpm at 100km/h. I've used a tyre of 650mm diameter for all these figures. This is ~3% bigger than a 245/45R17 but couldn't be bothered changing it.

It does appear the 140hp tdi has the best gearing for economy. The 170hp are geared a bit lower for pulling power and the 1.6tdis are geared a little lower because they don't have the torque.

[simonsheil]

My Passat is on 235/40/18, interesting on the 4x4 gear ratio as I would have had the cc in this configuration if it was available in the UK.

[Kiwibacon]

My Passat is on 235/40/18, interesting on the 4x4 gear ratio as I would have had the cc in this configuration if it was available in the UK.

The theoretical size of those (multiply width by profile x 2 plus rim dia) is 645mm.

What driveline is in your passat and do you know the rpm at 100km/h?

[Henrik Frontoviki Sandb]

how will my change in tire size influence fuel economy ? From 225 45 17 up till 225 50 17... I think its about 3,5 prs ? Does anybody know ? Thanks in advance ?

[Kiwibacon]

how will my change in tire size influence fuel economy ? From 225 45 17 up till 225 50 17... I think its about 3,5 prs ? Does anybody know ? Thanks in advance ?

It is mainly the different diameter which causes the computer and odometer to record a different distance travelled.

A lot of 4wd owners think bigger diameter tyres cause a big drop in fuel economy, but it is not the diameter of the tyres that is the problem. Rather that they are fitting wider and much chunkier tyres with more rolling resistance.

[Henrik Frontoviki Sandb]

ok thanks ! So diameter doesn alone cause any change !

[Kiwibacon]

If you scale the fuel economy numbers by the change in diameter, you should get the same result. This works well on my cars.