300tdi miles per gallon

And they aint a linear guage either.
thats why it teks agis t get thru the first quarter tank yet the last quater just seems like it evaporates

mines 1995.just done wrexham to perth scotland used £45.is that average for 70ish motorways?then ron around perthshire hill climb rally.down m74.a66.a1 to york then wrexham.779miles total £110 approx total fuel.i dont think thats to bad?i find it slower than my old 200series manual and brakes not as good unless its just me not used to it yet.im after cheap roofrack and dog gaurd net in near future.duno how rack will reduce mpg?not had the auto off road properly yet.

Hi. I'm reading this post with interest. I have hd my 300 TDI 96plate, manual, for 3 weeks now. It's got the big tyres (not sure of the size at the moment). I have yet to service it (i'll get the stuff from newark this weekend), and it still has the egr, and "cat" in place. It done 200k. I have just done 210 miles on half a tank (still only 99.9 a litre at the moment).
Does that sound about right?

Just to add my own two pen'orth...

It's possible that removing one of the exhaust boxes has caused a reduction in back pressure. I remember from my triumph tweaking days that a straight through exhaust had the effect of raising the 'power band' slightly-perhaps 3-400 revs. The car felt more revvy but lost a bit of low down torque in exchange for the gain higher up the range. There was also a commensurate decrease in economy in exchange for the added fun factor, possibly caused by the car needing to be driven in a more sporty fashion... It sounded glorious though, especially in tunnels!

I suspect you might be enjoying a similar effect.

FWIW I get 525 or so from a full tank with my manual 300tdi at 70ish and I'm sure I could improve on that if I stuck to 60. Not very good at sticking to that experiment though

Hi guys,
Just thought i'd add a bit of info for those guys running non- standard wheels/tyres from my own findings - admittedly this is on my bora 1.9Tdi. With the standard 16" alloy wheels running 205/55/16 quality tyres i was getting an avg 56mpg - due to my vanity i changed to some aftermarket 17" wheels running 225/45/17 quality tyres - the rolling radius is nearly identical (2% out i think) however each wheel now weighs an extra 2kg and my mpg reduced to 51mpg for the same journey. Now 2kg may not sound much but don't forget this is rotational weight and therefor it is a significanyt increase. Note: i tried some budget tyres but these added a further 2kg over the quality tyres. So even if your wheels and tyres give the same or similar rolling radius to standard it may be worth just weighing a wheel and tyre and comparing it to the standard wheel and tyre weight. Just my 2penneth worth.
P.S My wifes 200Tdi returns 27mpg all day long but she does an amount of motorway driving @ 70mph - so i suspect it'd increase if she slowed up a bit!
Cheers
Andy

me i get ~30mpg from a de-egr'ed, K&N'ed, 300tdi with about 3ton of armour and winch on the front. that said I also run it on an average of 40% WVO

SWAMPTHANG said:

well guys mine is an auto disco with an EDC and 26mpg sounds fantastic. Not good at maths so I will let you all work it out! last time I was home (6 weeks ago) i was filling my Tdi 300 auto for 86 quid and was getting 380 to the tank ful. That was pottering around town with some but not many average runs.

My TD5 DISCO gets at least 100 miles more from a tank full doing the same stuff.

If anyone can be bothered, THE QUESTION IS WHAT IS THE MPG?? =

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your tdi is doing 21 mpg as it worked out as follows, 86 quid at say 1.05p a litre means you have put 18 gallons in then 380 divided by 18 gives you 21.1 nad if your tdi is doing 480 a tank then that 26

courier said:

mine is the other way speedo reads 60 satnav reads 55

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sat nav are not accurate they do not take into account wether the ground is level or not so if going up or down a hill evena sligth one will throw out the sat nav and most car sat navs are only accurate to about 5 metres anyway, 5 metres at speed can make massive differences to speed, i would trust my car over sat nav any day.

tonkaboy said:

It's possible that removing one of the exhaust boxes has caused a reduction in back pressure. I remember from my triumph tweaking days that a straight through exhaust had the effect of raising the 'power band' slightly-perhaps 3-400 revs. The car felt more revvy but lost a bit of low down torque in exchange for the gain higher up the range. There was also a commensurate decrease in economy in exchange for the added fun factor, possibly caused by the car needing to be driven in a more sporty fashion... It sounded glorious though, especially in tunnels!

I suspect you might be enjoying a similar effect.

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Hi Tonkatoy, I'm guessing that was a petrol engine in the Triumph? If so, the effect you describe is similar to the one I get on my Bandit 1200 with a straight-thru pipe. This is in part due to petrol engines and their lower compression ratios needing the "scavenging" effect of the exhaust.

This does not apply to diesel and in particular turbo diesel engines as they have a much higher compression ratio therefore they "empty-out" no matter what style of exhaust system is in place.

thebiglad said:

Hi Tonkatoy, I'm guessing that was a petrol engine in the Triumph? If so, the effect you describe is similar to the one I get on my Bandit 1200 with a straight-thru pipe. This is in part due to petrol engines and their lower compression ratios needing the "scavenging" effect of the exhaust.

This does not apply to diesel and in particular turbo diesel engines as they have a much higher compression ratio therefore they "empty-out" no matter what style of exhaust system is in place.

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Yes, Biglad, that makes sense to me. It was a petrol engine Spitfire and the improvement a 4-2-1 manifold and straight through box made was amazing once I'd enriched the carbs slightly. You just had to drive it hard tho...

brainboy81 said:

sat nav are not accurate they do not take into account wether the ground is level or not so if going up or down a hill evena sligth one will throw out the sat nav and most car sat navs are only accurate to about 5 metres anyway, 5 metres at speed can make massive differences to speed, i would trust my car over sat nav any day.

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are you havin a larf ?

tonkaboy said:

Yes, Biglad, that makes sense to me. It was a petrol engine Spitfire and the improvement a 4-2-1 manifold and straight through box made was amazing once I'd enriched the carbs slightly. You just had to drive it hard tho...

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I know where you are coming from. As a nipper I had a few triumphs including a mkII or III Spitfire with a vitesse straight six in it, then when that fell to bits, I managed to get hold of the MD's old but great Triumph 2000 with overdrive on third and forth.

Old mans car I know but it was very comfy for the ladeeeeeezzzzz

Sean said:

are you havin a larf ?

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Nope car sat navs like tom tom are cheap and cheerful and do a responsible job for there cost but there receivers are small and not very accurate to within 5 metres is crap comapred to some of the measure equipment used for site measuring witch is accurate to within a few cm's. As for speed they estimate speed based on distance traveled by measuring 2 points and a time, firtsly the distance traveled is 2 fixed points not taking into account of elevation and not necessarly very accurate (within 5 metres). Your speedo wokrs by couting revolutions in the gear box and using simple maths if there is no wheel spin it takes an actual distance travels by time measurement.

brainboy81 said:

Nope car sat navs like tom tom are cheap and cheerful and do a responsible job for there cost but there receivers are small and not very accurate to within 5 metres is crap comapred to some of the measure equipment used for site measuring witch is accurate to within a few cm's. As for speed they estimate speed based on distance traveled by measuring 2 points and a time, firtsly the distance traveled is 2 fixed points not taking into account of elevation and not necessarly very accurate (within 5 metres). Your speedo wokrs by couting revolutions in the gear box and using simple maths if there is no wheel spin it takes an actual distance travels by time measurement.

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you clearly were having a larf

so then, tell me what happens to the accuracy of your vehicle speedo when you fit new tyres, or you over or under inflate them ?

Sean said:

you clearly were having a larf

so then, tell me what happens to the accuracy of your vehicle speedo when you fit new tyres, or you over or under inflate them ?

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my speedo can be up to 6 mph out since fitting taller tyres according to my sat nav

zak119 said:

my speedo can be up to 6 mph out since fitting taller tyres according to my sat nav

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i can well believe that, am just interested in what Brainy Boy's explanation is

zak119 said:

my speedo can be up to 6 mph out since fitting taller tyres according to my sat nav

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if you have non standard tyres of course its out but if you have factory fitted wheel and tyres then your speedo will be calibrated correctly

how does taller tyres alter the revolutions in the gearbox or am i missin something

brainboy81 said:

if you have non standard tyres of course its out but if you have factory fitted wheel and tyres then your speedo will be calibrated correctly

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what about accounting for tyre wear ?

zak119 said:

how does taller tyres alter the revolutions in the gearbox or am i missin something

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It doesn't. What it does do, is mean with a larger circumference you're actually traveling further per gearbox rev than expected.