Fuel Economy.

On my work commute which is door to door dual carriageway/motorway, I easily acheive 33mpg out of my V6 3.0 Petrol S Type. Sometimes a bit more. The "book" says (and honestjohn realworld mpg says) I should get about 27mpg, so clearly the "drive" in question is very economical

What do forum members think I would get out of a well maintained 2.7Diesel S Type - the "book" say 36mpg, which isn't much better than I am getting out the petrol, but I reckon I would do a lot better, given the figures above.

Diesel S Type owners.... please answer

 

Hi guygamps

I managed to achieve a 42 mpg on a non rushed trip, though I was careful as I wanted to see what I could get. Have to say I was really pleased with that 42, but I average 26 round town and a 34 or so where I drive normally without trying to conserve fuel. Hope this helps. I love the poke that my diesel has when you want it, with economy on the other hand.

 

Hello guygamps and baggienigel . . . and greetings from the far side down under.

I normally avoid these questions like poison. At best, individual driving styles make large variances inevitable. At worst, they can either raise unrealistic expectations or barely concealed disbelief. I'm not being coy; I just avoid quoting my experience other than the following; gained mostly from Jaguar (UK) and (Aus) and via TSBs, trade journals and contemporary road tests. Unfortunately, I cannot see which MY either of you have. Have you delved into the many hundreds of threads on the UK Forum for 2.7L TTD chat generally and fuel consumption in particular? OK; a bit long-winded but here goes . . .

The post MY06 2.7L TTD bares about as much resemblance to its forerunner as to a well timed Ford farm tractor . . . I mean no disrespect . . . I own several incredibly powerful Ford tractors. But careful research will prove the vast extent of the upgrades that occurred and which finally allowed us to see this Jaguar diesel variant in this country . . .

• redesign of both turbos and controller module;
• redesign of both injectors and control strategies;
• injectors acquired up to 8 pulsed events per engine cycle;
• injectors now far finer and programmable, steerable spray pattern;
• redesign of EGR system;
• redesign of DPF system;
• redesign and flash upgraded ECM firmware.

These upgrades to diesel power plant brought dramatic improvements in both emissions and fuel consumption. The tragedy is that with such huge (and successful) changes, so few diesel equipped cars were produced in 2007/8. Moreover, beyond your home market (UK) and much of Europe, I know of no other countries other than Australia and (possibly) New Zealand to ever see these vastly improved diesel models . . . via Jaguar (Australia), I know of only 3 others than mine on the entire east coast of Australia.

You may also be interested in the like-for-like road tests we reported here many months ago, on fuel consumption variances arising from two sets of simultaneous runs where rims+tyres were swapped between runs from otherwise identical cars. One set (mine) were Pirelli P-zero on 18x8 Mercury rims; the other were 97Y Kumho Asymmetric on 20x9 (front) and 20x10 (rear) after-market alloys. Fuel consumption was first 10% then 7% higher on the wider rims+tyres - an average of nearly 9%!

Having yesterday driven a 650Km trip in our MY07 under precisely your conditions (120Km/hr motorway for hour after hour) to attend our JaguarForums InterRegional meet on just half a tank of fuel, I would be mightily disappointed with only 36mpg. Perhaps that is the norm for the older engines - certainly not the latter - and my fill-to-fill records are more accurate than generalizing from hours of watching instantaneous fuel consumptions of 4-5L/100Km (47-58mpg) on a motorway trailing throttle or cruise control.

Best wishes,

Ken

 

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If anybody is going to respond to this thread, then may I suggest we keep to the topic posed by the OP . . .

• personal experience of 2.7L TTD fuel consumption;
• steady state flat running on motorways;
• in deference to the earlier posts, either stick to or correct for UK miles per imperial (UK) gallon.

And because of my earlier comments about the extent of >MY06 Upgrade . . .

• the MY or rounded last 6 of VIN because I predict a sizable diff in the latter variant

I'm not suggesting petrol fuel consumptions are irrelevant, because the OP seems keen to compare eventually , , , but they won't help in any way a discussion of diesel fuel efficiency. Note, I avoid the issue of "cost of running" because there are far too many variables in that beeswax for any useful cost comparisons. So, by way of example (and breaking my self imposed rule) I'll start the ball rolling . . .

• MY07; VIN final 6 is around N80XXX; with 40% worn Pirelli 245/45 P-zeros on 8x18 rims;
• between 53 and 58 mpg for flat steady120Km/hr (75mph) multi-lane motorway trips of at least 100Km but up to say 500Km distances.

Anyone else? Especially the pre MY06 models?

Ken

 

Fuel consumption topics can be quite tricky. Also it depends on the type of road you are driving. On the highway it is normal that your average mpg is higher than the one given by Jaguar. In town I average about 27 mpg.

 

There just isn't that many around as compared to gas/petrol powered. None imported to North America, which is a shame.

 

+1 Mikey; both in rarity outside of UK/Europe, and also the regret.

To others posting, my earlier comments were not designed to stifle debate - I too am interested in others' findings, but as already pointed out, these cars are virtually unknown beyond the UK/Europe market (that's the letter "A" in position 4 in your VIN#) and only at the end, Australasia.

Any other owners?
Ken

 

Yes, except in cities where diesels dump NOx & PM with dire health effects. Out of cities you've the space (unlike here) to let it dilute and just be harmful.