Fuel and defender performance.....

[smokinv8]

Slightly O/T but in my modified Nissan 200sx it is recommended not to use the manufacturers reccomendation of 97ron fuel but to upgrade to 99ron (like Shell Vpower or BP ultimate) to prevent engine detonation (why is beyond my knowledge)but I actually found that I had poorer fuel economy and no performance enhancement using the higher ron fuel

Back O/T, I have used both standard diesel and "performance" diesels in my old L200 and found myself that the performance increase using BP Ultimate was immense. Acceleration and power wise I mean, not economy.

Ive yet to try the difference in my 90 but I will following this thread.

[Retroanaconda]

Really interesting topic.............but no figures?? what genuine tank top to tank top mpg are you guys getting from your 200 tdi defenders? My ex Mod 90 was doing 30 mpg on mixed use keeping below 60 on the motorway with a 2.5 NA motor and Goodyear G90s 33 on a good day. - now with the 200 tdi gen defender motor.........I struggle for 28? I know I use the power a bit more - but same truck same tyres........Im dissaponted!

The Devon run thing? I have made this run many times in / on many vehicles. It is very noticable particularly on a bike that there is a strong prevailing wind from Devon right up the M5 - it really makes a big difference!!

I average 30mpg in my 90 (genuine 200Tdi, 150,000 miles), with a varied range of driving. Mostly local roads but with a few higher-speed (50+) runs. That's on 245/75/R16 tyres, I imagine that with 235/85/R16s on there I'd get slightly more MPG on the higher speed runs, and slightly less on shorter and more stop-start laden runs.

Never noticed a difference in fuel the few times I have bought anything other than Tesco diesel. Perhaps one day I shall try someone elses brand and see. So much of it is down to chance though, there are so many factors in the performance/top speed that attributing it to purely fuel without controlled test conditions is all but impossible.

[reb78]

Never noticed a difference in fuel the few times I have bought anything other than Tesco diesel. Perhaps one day I shall try someone elses brand and see. So much of it is down to chance though, there are so many factors in the performance/top speed that attributing it to purely fuel without controlled test conditions is all but impossible.

I would normally have agreed with this bit, but nothing changed in between fill ups other than the diesel. I literally drove to Devon, had a meeting filled up and turned around. The amount of difference i noticed almost immediately after re-fuelling was pretty crazy, otherwise i wouldnt have posted it. Tesco are also going to get a complaint letter (not that i expect anything to be done), and again i would not normally spend my time on that but again the difference was so much. I will work out some mpg figures, but they arent really comparable to other peoples trucks as tyre type and size, fact my speedo overreads, my overdive and the brownchurch rack will mean my figures are not comparable to those from your vehicles. I dont intend to do another tank on the tesco diesel to work out the economy on that for comparison!!

One thing i would add again is that i dont think i would have noticed this difference on short runs at moderate speeds - it was that top end speed and responsiveness that just dissappeared that made me notice it. Pootling around town, i dont think i would have told the difference.

[JJB Serenity]

before changing my tyres (to a larger radius and to MT's from AT's) I could average about 32 mpg in my 200tdi on ordinary Shell, BP or Total diesel. On BP Ultimate and the Shell equivalent I was getting around 38 - 40mpg and could achieve better top speeds and the engine ran quieter and smoother. I worked out that the extra milage was saving me money even where I was paying an extra 6 - 8 pence for the Ultimate.

[pinhead]

Very interesting topic

I don't know what the difference is between regular and ultimate diesel but I guess it has a higher cetane content this would indeed produce more power now a lot of folk on transit forum have started adding 2 stroke to a tank of diesel and reported massive improvements the theory is that modern diesel has lost a lot of it's lubricating properties and it helps pump and injectors to run how they were designed

The v power petrol is the best end of it has been tested by a drag racing engine builder that I know in controlled conditions with his dyno and a small block chevy and it consistently made more power and allowed more timing before any detonation than all the other so called super fuels all street eliminator cars run v power

[PaulN]

It is indeed an interesting topic.....

" folk on transit forum have started adding 2 stroke to a tank of diesel and reported massive improvements "

You mean the oil rather than a made up mix with unleaded? - proportions?

" massive improvements " in what ?

[pinhead]

It apparently (I have not tried this yet but am very tempted) smooths out the running and quitens it down with fuel economy improving after a tank or 2

And yes it does not have any unleaded in just a bottle full to a tank of diesel they are avoiding the red coloured stuff for obvious reasons

Also this is being used on mk7s with the common rail engines without problem

Maybe worth going over there and having a look at afew posts about this and making your own mind up but some transits do massive mileages and a couple of mpg could be thousand's over the year

[DaveSIIA]

My 300Tdi 110 doesn't seem to run as well on supermarket own brand fuels compared to Esso/Shell/BP. The loss is typically 10-15% in terms of MPG and it is noticably sluggish at the top end. I have records of (most) fuel purchases going back over the past 300K miles and there is a definite trend. There is also a consistent slight reduction of MPG during winter months, possibly due to anti-waxing additives. Journey patterns are fairly regular, with frequent long distance motorway / fast A road runs that use two tank fulls for the return journey.