Shell V Power Nitro + Diesel or Texaco Supreme Diesel

[xantiagreen]

I'm looking for better MPG currently getting 33-35mpg town driving a doing just under 15 miles a day.

Have not used any fuel additive since buying car back in Sep 2013 only using Forte Cleaner. Used Shell fuelsave diesel up until Jan 2014 when it changed to Texaco have used Standard diesel up to March then changed to their supreme diesel can't say I have noticed any improvement in mpg or response feels the same. Is their any point in trying Shell V-power nitro + diesel, or should I stick with Texaco diesel supreme. My yearly mileage is less than 3000 miles so I will be servicing the car yearly.

Any point in adding an oil treatment/additive, does not use any oil or smoke other than slight dark to light greyish haze on start up. There are no mods or re-maps, car is currently on 109k with full service history mainly Citroen specialists 2-3 at a non Citroen specialist garage, I'm the 2nd owner and I drive lethargically only having to change gears at the last second and never rev over 1800 rpm. Car was on diagnostics and no issues on engine side of things.

Engine is running on Total quartz 9000 5/40 fully synthetic.

Any advice on what I can do to get better mpg and to prolong the life of this xanty. Also sticker on inside front door says front tyres should be at 2.4 bar and rears at 2.2 is that right (seems a lot)

Thanks in advance..

[Hell Razor5543]

The tyre pressures seem OK to me (14.7 PSI to 1 BAR), so 36 PSI and 33PSI. The spare is probably 2.7 BAR (about 41 PSI).

The fuel economy also seems about right considering where you are driving. I had a 110HP HDi, and would struggle to hit 40MPG round town. That engine is really a cruiser. I once did an economy run to see family in Birmingham, and got 61.3MPG. Mind you, normal motorway driving dropped that a bit, but still better than 50MPG.

[THELABMAN]

I can't comment on your choice of diesel but the tyre pressures sound about right to me as all three Xantia I had run on the same figures I used 35psi in the front and 33 psi for the rear that was in the 1.9TD ......

[xantiagreen]

What brand of diesel do you use and do you add any additives to fuel or engine oil?

[qprdude]

Tesco or Morrison's for me. Tried V power all the way on my last Aberdeen Woking trip and it made bugger all difference to either power or MPG (Slightly less in fact). I tell a lie, it emptied my wallet a bit quicker.
Tyre pressures on the new C5 are 2.2 all round I think, and 2.4 on the rears with full load. Does it depend on the rim size? Probably not.

[rory_perrett]

Tyre pressures are correct.

I have kept comprehensive mpg data for a number of cars (all diesel) for the best part of 20 years and from all this I have concluded that there are just too many variables to really make anything other than general observations. The two things that have the biggest impact are air temperature and the driver. On an mpg graph there is a definite drop in winter and rise in summer. In general supermarket fuel seems to give slightly less mpg than brands but it's very marginal. I have not seen any benefit from Shell V power over Shell fuel saver or other Brands. Exclusively town drive gives 38 - 40 mpg, motorway cursing at circa 60 mph get upper 50s mpg and in mix driving and a sensible right foot can give an average of between 50 and 55mpg.

Towing and full roof racks make a difference but I still come back to driving style being the biggest factor in the mpg achieved.

[isisalar]

Have had my HDI for about 18 months now, similar driving conditions and was getting similar milage. To try and improve things I first got it on a Lexia which showed up a dodgy MAF and no.1 injector faulty, replaced both and performance improved and economy slightly.
Could still hear the injector ticking slightly so used Slick 50 fuel system treatment, which is very effective I've found, improvement again, but still the ticking remained.
About 6 months ago I decided to give the V power an extended trial, more for its claimed cleaning properties than anything else. To my delight the performance is improving with every fill and the ticking is slowly but surely getting better. A good Italian tune up made a massive difference too.
Gave the car a VERY hard 15 mile thrash down a motorway a few weeks ago and there was some sort of transformation, the turbo now seems to work much more than it ever did, and I think economy is also better, it feels like a completely different car.
One thing that may be relevant to the transformation is that the on off power is now far less abrupt and now the car when slowing down will tick over at about 980 rpm and then drop to about 820rpm when stationary. Previously dropped straight to 820rpm. Any ideas?
So a big yes from me for the V power, together with a damn good thrashing!
Cheers
Paul

[Peter.N.]

I started running diesels in 1959 and have run them continuously for the last 30 years and have never noticed an appreciable difference between fuels. Assuming that everything is running as it should, difficult to be otherwise on an IDI engine, the main factor affecting fuel consumption is driving style and as Rory says the ambient temperature, tyre pressures makes very little difference either, I use to run my 2.1.XMs at below recommended pressure because it improved the ride and still got 50+ mpg on our annual Scottish trips.

I have a C5 and 406 2.0. Hdi now and the worst consumption I have had has been the high 40s and the best 67.8mpg over 650 miles returning from Scotland on a very hot day, the 406 averages around 50mpg with 60+ on a long journey. I do though drive very gently, rarely exceeding 60 mph or 2000 rpm and we live in a rural area.

If you can bring yourself to drive sympathetically to the car, avoid heavy braking and hard acceleration ,change up as early as possible and keep the revs down to around 2000 you will see an improvement, I understand many people don't have the patience, I didn't used to until I was covering 1000s of miles on the motorways, I then found that driving with the lorries in the slow lane made a much more relaxing and less tiring journey and now I'm old its stuck, you would be amazed to see the difference in consumption if you could discipline yourself to do that.

Peter

[xantiagreen]

Tyre pressures are correct.

If the tyre pressures for xantia's are 2.4 front and 2.2 rear i assume that would be fully laden, then what would be the un laden pressure be. On nearly every car i have seen or driven they have the pressure for 2 passengers and small luggage and then pressure for 4 or 5 passengers and large luggage.

Don'tcarry anything in the boot other than bottle of lhm and jump cables and only have 4 passengers that are under 8 yrs of age so they dont weigh more than 12 stones altogether including me there's 25 stones of passenger and driver weight in the car daily one way then just my self back home.

[SwissSPEC]

If you're only doing 3000 miles, why are you bothered about trying to get a few extra miles to the gallon? I've tried the so called better diesel fuel, not one iota of difference imho except you pay more for it. The only fuel i've noticed was the Shell stuff which claimed to give you an extra 10 miles to the tank, & seeing as it was the same price as the supermarket stuff i decided to give it a go. I did get that extra 10 miles to the tank, but when the price went up i just stuck to the supermarket stuff.

You don't mention how many miles your engine has on it? I suspect that if you always drive slowly all of the time, the exhaust will fill up with plenty of black crud, i usually do an italian tune up every week to clear all the rubbish out.

When you say you're only doing 15 miles a day, how many times to you stop? The engine will barely get to operating temperature, hence why fuel economy will be what you're experiencing. If you really want to get better fuel economy, i would try this place, it's cheap & should hopefully give you what you need The stage 1 would be the best value imho: http://www.hdi-tuning.co.uk/ecu-remappi ... DI110.html" onclick="window.open(this.href);return false;

[Peter.N.]

The OP doesn't say which car he is using, I assumed from the list that it was the BX, if its the Hdi that's a terrible consumption, I don't think I could get mine that low if I really tried.

Peter

[Hell Razor5543]

He does say he is using the Xantia, but it is town driving. When I had a 110 HP HDi Xantia I also found that around town it had poor MPG, but at cruising speeds it had exceptional MPG.

[Peter.N.]

He does say he is using the Xantia, but it is town driving. When I had a 110 HP HDi Xantia I also found that around town it had poor MPG, but it cruising speeds it had exceptional MPG.

Sorry only just spotted that that does sound very bad though even for town driving. He needs to take it on a bit of open road to test it properly, at a steady 60 mph it should do around 60 mpg.

Peter

[Hell Razor5543]

It might also be worth running an injector cleaner through the tank. I would guess (based on the original post, 15 miles a day around town) that the engine isn't getting to its' optimal temperature for very long (if at all), so the injectors might be getting clogged. I might have to do that for Gracie, as I haven't done that much distance driving recently.

[myglaren]

It might also be worth running an injector cleaner through the tank. I would guess (based on the original post, 15 miles a day around town) that the engine isn't getting to its' optimal temperature for very long (if at all), so the injectors might be getting clogged. I might have to do that for Gracie, as I haven't done that much distance driving recently.

Will you be going to the X-rally James?