D4 TDV6 & SDV6 same fuel economy what the?

[Greatsouthernland]

The MY14 TDV6 155kw and SDV6 183kw, both have same urban/extra urban and combined fuel usage. Both twin turbo. The TD is approx 1.5 secs slower 0-100kmh as well.

How does that work? I'm obviously missing something simple this late at night, but I thought if the engine in the TD was detuned, it would also save fuel?

Apologies if this becomes a hang crap on the newbie thread...:angel:

...Tare mass is the same too. Gearbox the same, so I assume ratios the same...work brain...:eek:

[Graeme]

Presumably the SDV6 doesn't have to work any harder than the TDV6 in the particular test programme so doesn't use any more fuel. Afterall, its not a race.

[Greatsouthernland]

So in the 'real world' the TD would use less fuel?

OR, because it's got less torque, it has to work harder and longer to move the same weight, so maybe more fuel - why would they offer this lower power version at the same time when it uses the same amount of fuel? Or is it just a slap in the face of those who want to save 10grand on the SD, so JLR say 'you're not worthy, have a detuned engine, otherwise the same if you want to skimp 10k, ha ha old chap'.

[FishSlap]

[Lotz-A-Landies]

Maybe its the fact that the SDV6 is more efficient developing more power from the same amount of fuel.

After all the TD is not de-tuned it's that the turbo arrangement is less developed than the SD which has usable boost over a longer rev range.

[DiscoMick]

It's the same engine, just being operated slightly differently, so why should there be any significant fuel consumption difference in normal motoring?

Sent from my GT-P5210 using AULRO mobile app

[Greatsouthernland]

Maybe its the fact that the SDV6 is more efficient developing more power from the same amount of fuel.

After all the TD is not de-tuned it's that the turbo arrangement is less developed than the SD which has usable boost over a longer rev range.

Thanks Lotza! The turbo(s) - I didn't know that... Now I don't understand why they can't just tune them differently...? Or, could I do it after market for around a grand and still be 9 grand in front and laugh all the way to the next service...where they void my warranty :o :oops2:

I'm leaning back to the D4 due to all the neg vibes I'm getting on this forum re the L322, especially lack of accessories I.e. Bull bar, snorkel, wheels.

[Greatsouthernland]

It's the same engine, just being operated slightly differently, so why should there be any significant fuel consumption difference in normal motoring?

Sent from my GT-P5210 using AULRO mobile app

My thinking....both engines towing the same size van/boat on the same road with the goal of maintaining the same speed as each other, keeping the traffic flowing etc. one has way more power and torque, same gear box, so theoretically (with no magic) the lower powered one would have to create more energy to mimic the more powerful one. Therefore, unless I'm missing something, it takes more fuel to make more power in identical scenarios.

[Greatsouthernland]

Presumably the SDV6 doesn't have to work any harder than the TDV6 in the particular test programme so doesn't use any more fuel. Afterall, its not a race.

Cheers Graeme, I would go with that if it was a bench test, BUT, they quote urban and highway, probably misleading, but I would assume this involves moving the vehicle at different speeds, requiring power and torque - hence fuel.

[Lotz-A-Landies]

There is more space for gear in the D4 so for travelling the D4 more usable.

[Greatsouthernland]

There is more space for gear in the D4 so for travelling the D4 more usable.

Agreed, a big factor for this family...

[Graeme]

Cheers Graeme, I would go with that if it was a bench test, BUT, they quote urban and highway, probably misleading, but I would assume this involves moving the vehicle at different speeds, requiring power and torque - hence fuel.The tests are indeed effectively bench tests involving a defined sequence of idling, stop-start driving at certain acceleration rates, driving at specified speeds for specified time intervals etc so as to be able to compare consumption across all manufacturers' vehicles. Manufacturers tune their engines and gearboxes to achieve best possible results for the tests, often to the detriment of driveability or fuel consumption under other circumstances. The tests apply to the smallest of engines so would be a walk in the park for a TDV6 so an SDV6 isn't going to get the opportunity to do more work to use more fuel.

[nat_89]

Agreed, a big factor for this family...

You'll love the D4 they will not disappoint just awesome all the space and engine and how they handle everything just a wicked machine love it!!

[Greatsouthernland]

2011 Land Rover Range Rover Vogue L322 TDV8 Autobiography 11MY Sports Automatic (http://www.carsales.com.au/dealer/details/Land-Rover-Range-Rover-Vogue-2011/AGC-AD-15868751/?Cr=0&sdmvc=1)

Nice, getting distracted.