BP Nectar and increased mpg - smokie
For tax reasons I maintain a log of all petrol bought, and mileage etc. I always brim the car at each fill so can calculate (roughly, as I know sometimes it is fuller than others) mpg per tankful.

I'd been a regular BP user until they stopped doing Argos points. AT that point I bought a tank of Tesco (cos it was convenient) and then a tank of Optimax (cos people here suggest improvements, but I didn't notice much) and ever since (a further 7 tankfuls, about 2000 miles) I have bought standard unleaded Shell.

Curiously, my mpg has risen from 24 - 27 mpg to 28 - 33 mpg over the exact same period. (R Reg Omega 3.0 MV6, 48.5k)

I don't believe the change in fuels has altered my driving style, and the journey type hasn't changed (mix of local journeys dropping kids off and longer business journeys).

Also the local Shell garage is the cheapest for miles around @ 72.9 as opposed to 74.9 everywhere else.

I wonder if the tankful of Optimax had a magical effect? Or maybe the local garage has Optimax in the unleaded tanks by mistake...
BP Nectar and increased mpg - revilo
Do you have any further information on this subject. Is it worth paying a bit extra for Shell?
I drive a 2.5 Omega and also pull a caravan. Towing I get approx 17-18mpg and solo upto 30mpg on long distance motorway driving.
Have you considered modifications? eg Superchip. This gives about a 10% increase in torque apparently.

By the way have you had your cambelt changed? HJ recommends changing mine at 40k (oops - too late as I've done 50k but at least the belt hasn't snapped) better get it seen to!>> For tax reasons I maintain a log of all petrol bought,
and mileage etc. I always brim the car at each fill
so can calculate (roughly, as I know sometimes it is fuller
than others) mpg per tankful.
I'd been a regular BP user until they stopped doing Argos
points. AT that point I bought a tank of Tesco (cos
it was convenient) and then a tank of Optimax (cos people
here suggest improvements, but I didn't notice much) and ever since
(a further 7 tankfuls, about 2000 miles) I have bought standard
unleaded Shell.
Curiously, my mpg has risen from 24 - 27 mpg to
28 - 33 mpg over the exact same period. (R Reg
Omega 3.0 MV6, 48.5k)
I don't believe the change in fuels has altered my driving
style, and the journey type hasn't changed (mix of local journeys
dropping kids off and longer business journeys).
Also the local Shell garage is the cheapest for miles around
@ 72.9 as opposed to 74.9 everywhere else.
I wonder if the tankful of Optimax had a magical effect?
Or maybe the local garage has Optimax in the unleaded tanks
by mistake...

BP Nectar and increased mpg - mal
72.9!!!!!!!! were being ripped of up in the North East.

Cheapest here is 76.9.as far as I know.
BP Nectar and increased mpg - smokie
Mal - my original post was 4 months old, hence the cheap petrol!

I was hoping no-one would ever respond to this thread. I realised a week after posting, with ever increasing mpg, that there was a logic error in my spreadsheet!

However, I now do more motorway than off motorway and it is definitely beneficial to the mpg by a few.
BP Nectar and increased mpg - mal
Smokie, thats yet another lesson I have learned, just never noticed the date owing the fact that there can be great regional differences in petrol prices.
Revilo must also take part of the blame for dragging this up from last November.

............OK,OK,will open my eyes in future.................

BP Nectar and increased mpg - caz
same here in the south, its 77.9 in most petrol stations in bournemouth, what a rip off!
BP Nectar and increased mpg - Trilly
I also have a R reg MV6 estate 53k and get on average 22mpg according to the onboard computer. Low mpg is due to other half driving around in the week for short trips.

The next time it comes up to fill up time will have a go at Shell to see what happens. Cars have done similar miles but sounds like your journeys are longer or we have heaver feet :-)

And yes I did change cam belt at just over 40k,had one go once and what a mess that caused, Citroen BX at 40k....
BP Nectar and increased mpg - smokie
Trilly please note there were errors in my original post. Overall since last April my mpg is about 24