Thread: D4 TDV6 & SDV6 same fuel economy what the?

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.

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'.

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.

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

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Originally Posted by 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.

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

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.

Originally Posted by DiscoMick

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

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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.

Originally Posted by 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.

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.

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