[TonyXJR]

With the third birthday of my Autobiography ownership (and about the second birthday of the unicorn hunt), I actually did the arithmetic.

In three years I have averaged a measured miles per litre of 7.15. This is about 32.53 miles per gallon. In that time I have had it serviced annually, and additionally I have had four oil changes (inc. AdBlue). I don't do my own oily ragging, so it cost me £121.92 + £129.92 + £160.05 + £173.84 = £585.73. I didn't do any extra in the first year, hence at the beginning of year two I needed a throttle body: £1,146.28. Total diesel related cost: £1,732.01.

My diesel cost a total of £3,972.28 - an average cost of £1.63 per litre. Petrol is about 20p cheaper than diesel, so I will use a petrol price of £1.43 for the next bit.

If I had done the same mileage in a petrol car (and assuming all other things being equal - DVD players, dash cams, servicing, maps, AC regs, boot mats etc.), I would have needed to average 6.2763 miles per litre (about 28.5 miles per gallon) to break even with the all up cost of running a diesel.

So the question is for all you petrol X351 owners: what is your average fuel consumption, and does it beat 28.5 mpg (measured)?

It may be that the unicorn search is about to be abandoned, unless someone can tell me that it makes any sense at all (other then the sound, obviously)

It's from an XFR, so heavier than an XJ (though maybe not much with all the extra kit and LWB), but I would say nowhere near. My driving was all long runs & averaged over about 25k miles.

 

[JimC64]

As the bulk of your trips are supposedly mostly stop / start and a few miles here n there Chris, with the odd long distance job thrown in now and then, you'd need to be working on absolute worst case scenario to get a reasonably accurate picture.

Another nice graph and info from Tony above may help, but then mostly long runs, so maybe not

Jim

 

[mac_doctor]

I reckon if you get 32mpg in the diesel, you won’t see 28 in the petrol. More like 22.

However, are you sure about your numbers?
I might have missed something but roughly;
6000k miles a year @ 32.5mpg is around £1350. (163p)
6000k miles a year @ 22.5mpg is around £1750 (143p)
So £400 a year @6k miles, still under your diesel overspend.

Thanks for the reality check - you are right.

I calculated the petrol mileage against only the diesel cost: I didn't include the oil changes and sundries. To match the spend I only need to get 20 mpg from the petrol. That makes the economics much better, even for SWMBO maths!

OK - the unicorn hunt is still on. @Renegade2 - are you bored with my car yet?

 

[mac_doctor]

In comparison to that with the same engine, I’m averaging just over 36mpg to a full tank of diesel. With usually just one main service a year. All I’ve had to change in that time is an ABS sensor totalling £63.

I had mine during lockdown: 20/21 I got 29.3 mpg, 21/22 I got 21.5, and 22/23 I got 34.6 - which is a lot nearer your 36. And we all know that the EURO6 X351 architecture is worse than the X260.

 

[mac_doctor]

Spotted a great number on the odometer:

Then looked again.

Damn.

 

[#steve]

Dyslexic fans will love that.

 

[mac_doctor]

Another question. As Ian will confirm, I live on (the poor end of) a road that is frequented by some expensive motor cars. Jaguars are common, but we get Maserati, BMW, Mercedes, Lamborghini, Bentley, McLaren, even the occasional Ferrari down the street. But when I hear a loud car noise, and look out of the window to see what it is, it is always a Corsa. Why is this?

 

[Ian D]

Another question. As Ian will confirm, I live on (the poor end of) a road that is frequented by some expensive motor cars. Jaguars are common, but we get Maserati, BMW, Mercedes, Lamborghini, Bentley, McLaren, even the occasional Ferrari down the street. But when I hear a loud car noise, and look out of the window to see what it is, it is always a Corsa. Why is this?

I can confirm that the cars on your street, some of them are lovely. There’s a real nice 911 I always go past when I need to go into the village that I really like the look of.
As for Corsa’s, that’s just standard of those cars and the people/age group, was Fiesta ST’s not long ago, it was unusual to hear one that didn’t have a pop and bang remap.

 

[mac_doctor]

I hate car adverts:

 

[chris9369]

I hate car adverts:
View attachment 63112

What is wrong with that one? apart from it not being an Autobiography. The MPG is marginally better than the V8 but has far more power than the Diesel.

 

[XJ1983]

I hate car adverts:
View attachment 63112

On some websites I saw mine come up as Petrol when looked up via number plates. I wonder why that happens?

 

[mac_doctor]

What is wrong with that one?

There aren't many 3.0D (stands for diesel, as i understand it) petrol cars.

The MPG is marginally better than the V8 but has far more power than the Diesel.

That is why I include the 3.0 petrol in my searches. But car adverts that don't know whether they are advertising a diesel or a petrol are the bane of my life.

I was about to pull the trigger on a V8 (JAGUAR XJ - LO20 VAV), when it turned out that it had a diesel engine in it ("sorry", said the salesman "does that make a difference?")

 

[JimboV8]

I hate car adverts:
View attachment 63112

Why do you put yourself through this heartache.

 

[chris9369]

There aren't many 3.0D (stands for diesel, as i understand it) petrol cars.



That is why I include the 3.0 petrol in my searches. But car adverts that don't know whether they are advertising a diesel or a petrol are the bane of my life.

I was about to pull the trigger on a V8 (JAGUAR XJ - LO20 VAV), when it turned out that it had a diesel engine in it ("sorry", said the salesman "does that make a difference?")

There aren't many diesels with a power rating of 340PS either. I had looked at the 340PS rating which is the rating for the Petrol engine. DVLA have it listed as a diesel.
Unfortunately Autotrader is one of the worst places for advert errors. When I was looking for a convertible XK8 several Coupes came up in the searches. The salesman usually blames "the girl in the office" for the errors but why does no one ever check what they are listing.

 

[PetA]

There aren't many diesels with a power rating of 340PS either...

Are there any?..

 

[mac_doctor]

There aren't many diesels with a power rating of 340PS either. I had looked at the 340PS rating which is the rating for the Petrol engine. DVLA have it listed as a diesel.
Unfortunately Autotrader is one of the worst places for advert errors. When I was looking for a convertible XK8 several Coupes came up in the searches. The salesman usually blames "the girl in the office" for the errors but why does no one ever check what they are listing.

Having pointed out all the errors in the advert, I would just like to point out that you asked me what was wrong with it!

(Unfortunately I don't have the power ratings of all the engines that Jaguar have ever fitted to any engine at my fingertips - and I have no idea what a PS is either: I am stupid enough to rely on what I read - and then entitled enough to moan when I find out that it is bollocks)

When I saw that XJ50 listed as a V8, the salesman was on my third call (the one after I asked for a picture of the engine) before he told me that his boss had misidentified it. Difficult to blame Autotrader when the garage itself hasn't got a clue!

 

[#steve]

You could always download the Vehicle Smart app and check the details on there first before getting excited.

I use this on all the vehicles i collect and so far its been accurate.

 

[mac_doctor]

You could always download the Vehicle Smart app and check the details on there first before getting excited.

I use this on all the vehicles i collect and so far its been accurate.

Does it have any V8 Autobiographies?

 

[mac_doctor]

Not enough TVs, obviously, and way too short: but this one had me intrigued. Until I looked at the back. What's wrong with this picture?

 

[#steve]

Does it have any V8 Autobiographies?

Only if you have the reg number