General Posh diesel - can you spend more and save money?

[Doofer]

Has anyone else tried the various posh diesels that are about - Shell V-Power or BP Ultimate?

I did try BP Ultimate once, about a year ago and thought I got higher mpg (but I was driving on deserted A-roads in Scotland at the time). I'm currently trying Shell V-Power, and mpg seems to have stayed the same or even reduced. Plus the engine sounds more rattly - like it's permanently cold (even though it isn't).

I may have confused the issue by chucking Redex in with it - I didn't think about any possible interactions between it and whatever's in the V-Power.

My hope is that I can find a fuel that does increase mpg. As prices are now so high, the premium stuff is only a few % more, so it's worth having if it increases mpg a bit.

Has anyone else tried any of the posh stuff?

 

[DoIDon'tI]

Tried it not long after buying the car, no difference whatsoever. The only way I know of to keep mpg up is to drive sensibly (do the manual stop/start thing), maintain the car well and run some injector cleaner through every so often - sorry

 

[Caravadossi]

Fuels and their money
My 5-year-old Rover 75 Connoisseur SE CDTi diesel has covered 29,000 miles and will average 48 miles per gallon on a long run dropping to 43 on short runs. My independent garage has recommended Shell V Power to improve consumption and reduce engine wear. Do you consider the extra cost of V-Power is worth it? I will probably keep this car for about 3 years and average 10,000 miles a year. MS, Tonbridge (2010/08/07)

My recommendation is BP Ultimate DIESEL. Shell V-Power PETROL. I don’t recommend V-Power diesel over BP Ultimate Diesel, but I do recommend Shell V-Power Petrol petrol over any other petrol. HJ

Source:
http://www.honestjohn.co.uk/askhj/answer/14417/fuels-and-their-money

Personally I’m exclusively on ASDA diesel (I believe out of ConocoPhillips Humber refinery) – so can`t comment on any alternative. My o/a 2010 av.mpg was 41 mpg - & a tad shy of that for Q1/2011, maybe due to cold weather spec fuel & heavier tyres.

---------
55 Prestigio 1.9/16v 150 (61K mls)

 

[Mal126]

Fitted a TMC tuning box to my 1.9jtd 8v Croma a couple of months ago, well impressed with, m.p.g gone from 42 to an average of 51.6 mpg, really notice the difference. Would definately recommend, different car to drive as well.

 

[Doofer]

Fitted a TMC tuning box to my 1.9jtd 8v Croma a couple of months ago, well impressed with, m.p.g gone from 42 to an average of 51.6 mpg, really notice the difference. Would definately recommend, different car to drive as well.

Really? I've always been anti-mapping, but that's certainly a persuasive reason for thinking about it. Especially as it's £125, not the £100's I've seen for others.

How much of the increase do you think could be down to you driving more gently? Are you driving on similar roads to before? Any other changes to the car at the same time?

 

[Doofer]

There's a TMC box for sale on the forum here...

https://www.fiatforum.com/classifieds/showproduct.php?product=22268

"Worked really well when set to correct level but I've got no patience and it's costing me a load in extra fuel"

So it's either brilliant or crap! Any ideas about the setting to correct level bit? What's yours set to Mal126?

 

[cromachris]

In my experience the posh stuff is great on the motorway for increasing mpg, but round town it makes no difference. I think it's slightly more volatile, so when accellerating it will give you more of a pull, but will burn more than normal diesel.

I found that I had the knocking sound after using it for a while and did some research. From what I can remember the knock is caused by the flame wave-front occurring too soon within the engine - the ignition point needs to be at a very specific stage for it to drive the engine most efficiently. This stuff is more volatile so it ignites ever so slightly too soon. By puting Redex (other fuel additives are available ;-) ) in with the posh fuel you are exacerbating the problem. Last time I bought some additive I am sure that a lot of them had "for use with regular diesel" or other similar wording on the instructions.

I now use posh stuff a) when I can afford it and b) when the engine is starting to feel clogged.

I am pretty sure that the above is accurate, but it is quite conceivable that I could be talking from my bottom!

 

[Mal126]

Really? I've always been anti-mapping, but that's certainly a persuasive reason for thinking about it. Especially as it's £125, not the £100's I've seen for others.

How much of the increase do you think could be down to you driving more gently? Are you driving on similar roads to before? Any other changes to the car at the same time?

Was looking at remap but cost stopped me going that route, thought to myself after looking at tuning boxes and researching, that i would go for, have to say was sceptical, spoke to Daren at TMC, really helpful, actually when i mentioned fiat forum he charged me £95 but that was before vat increase etc, when the box arrived the internal potentiometer was set at around 12 o'clock, (best position for fuel economy and extra bhp, i thought what the hell i turned it to about 2.30 - 3 o'clock, took me 5 mins to fit, what a difference, have done nothing else to the car, exactly the same journeys, lots of hills where i live , the torque difference is great, also motorway journeys now a pleasure, just leave in same gear and accelerate, i drive quite hard all the time (i never drive gently), and still improved mpg, as i said well impressed, was thinking of turning potentiometer up further but on reflection think may be too much torque for the clutch at mo. Have you 8v or 16v ?, different boxes i think, if your ever near Cardiff you are more than welcome to drive my car and see what difference it makes.
As i said for the cost i'm well impressed !!

By the way have not changed my driving habits at all, have no association with TMC and have been involved with Fiat for the last 30yrs (christ that long) in various capacities.

regards

Mal

P.S. Go direct phone TMC and explain situation and explain member of FF

P.P.S. In fact for the time it takes, if you have an 8v, i could take off mine and put on yours for you to try, now thats an offer lol

 

[Doofer]

Thanks for all the info.

I've googled for "V-power knocking" and I'm not alone. Back to Morrisons with an occasional dab of Redex then.