Cold weather?

With the 130hp variant in a huge A6 Avant (5 speed box), I used to get 45-46mpg on a decent run. 41-43mpg general use.

But do remember that the car is 10 years old. Expecting it to be as efficient now as it was when new, or even as it was 5 years ago, is not realistic. Parts wear.

I'm often quick to criticise various aspects of the Octavia but on this occasion, I will spring to the defence of the 1.9 tdi engine that we share, as I have the very same engine as you have in your Seat.

Firstly, the BXE engine is not really a "risky" engine. Yes, there are a few reports of con rods letting go, but I researched this intensely and it seems that it's a fairly low frequency, but yes, possibly a bit more frequent than other engine codes. Some very dissatisfied owners made a lot of noise on various forums, but taken in context as to the literally tens of thousands of these engines, the failure rate is tiny. So I wouldn't be worrying too much. I've driven at high speed through Europe several times, without the engine ever missing a beat.

Onto fuel economy. The 1.9 PD is indeed an exceptionally economical engine. Noisy and rough, but I have never had less than 50 odd to the gallon, in fact the average is 53 mpg on this car. Last week, a 200 mile run to the Midlands at legal speeds gave me an indicated 60mpg, which will be a true 56 ish.

Looking up the 2 vehicles on Spiritmonitor, a European mpg real world database, gives 49mpg for the Octavia and 45 mpg for your Seat. Now your Seat has a greater frontal area and is probably heavier, which would explain that. Your 39 mpg is indeed poor and I suspect a binding brake or similar. It should do better, although my neighbour has a 1.6 Tdi CR Altea and struggles to better low 40s. Not a good engine by the way!

Thanks! I did not know about Spiritmonitor! Great Site. Also for the peace of mind about the BXE I am choosing not to be super stressed about it. There are way too many BXE around and this one is dated 07/02/15 so even if I pay attention to the rants it apparently affects the later ones. (I only paid £1400 for it with several dealer stamps and recent cambelt and dmf with receipts so...)

Don't know if your octy is a saloon or estate but I thought my Altea was heavier but is lighter than a passat and barely heavier than a golf mk5 but aerodynamics might be part of it as other suggest. Thanks for the tip about the 1.6 CR too I was considering that route too.

Any tip checking for the binding break? I was thinking of cleaning the EGR when I have some time and maybe be pumping up the 205/55/16 to 35psi instead of 32psi.

For now I will drop a few MPHs and live with it but would love to find more about it.

One of my ex colleagues had a 1.9PD Passat for years always getting 50+mpg, then traded up to a 2.0 Diesel Toledo (same shape as Altea), despite similar usage and driving technique he struggled to get 40mpg and often only mid 30's from the thing, he got rid quickly.

I wonder if the shape is particularly bad for drag.

I owned a VW Golf PD130 6 speed for 13 years, i would regularly get 60mpg on a motorway run driving within all the speed limits with occasional 80/85mph on down hill gradients to take advantage of gravity.

I would also drive to keep the engine at 2000revs where it produced maximum torque, which in 6th gear was an indicated 70mph.

Exceeding 70mph and regular higher revs through the gears resulted in a fuel penalty,although I would do so accelerating away from roundabouts on deristricted roads to ensure the turbo was well excercised

Town driving in the summer was 54/55mpg and winter 45/48 mpg

What year was your Golf? and was it a MK4 or MK5?

We had a 1.9 TDi Golf that would do a calculated 60 mpg on a holiday run. But the problem was the accuracy of the odometer. Our twice a year holiday route still uses the exact same roads as we did back in 1993. When we had the Golf it said it was 450 miles which surprised us since it was 425 miles in the old Bluebird. When we checked it with a Satnav it is actually 430 miles and AA Autoroute agrees with this figure.

So the 60 mpg calculated drops to 57 mpg when the correct distance is used.

The Leon I have just traded in also over read dostance but it was only by a small amount (435 miles to Scotland) and other cars I have owned since the Golf have all been pretty close. The Ford Focus was absolutely spot on.

Probably just another way of getting owners to think they are doing better MPG than they really manage.