Poor fuel economy on my 2002 TD5 Auto Discovery

[Anderzander]

I did a total of 272 miles and I filled it up again on the way home. 272 miles was the reading after I reset the trip meter on the 1st refill. I filled it to the brim again and I got 272 miles out of £42 of diesel at 128.9p a litre.

I am tired - but that seems to work out to be just under 38mpg .....

[CwazyWabbit]

I agree with your calcs

[Shackleton]

Mate I think there might be a fault with your fuel sender. Going by your description it sounds like you were filling it to the brim from empty. If you filled it to the brim and it cost £42 at £1.29/l, then you pumped roughly 32 litres of fuel. The D2 standard tank capacity is 95 litres (far as I can make out). So your tank wasn't actually empty, it was still well over half full. If there is a fault it could explain why you seem to be getting record breaking consumption figures.

[Anderzander]

Either something is amiss or he should be the proud owner of the two most economical Td5's in history

[Scotts90]

From memory it was about 23 gallons on my d2, almost choked the first time I filled it up from empty (only had 11 miles on the clock).

This did a consistent 550/560 to a tank which equated to 25mpg approx.

I don't think CJ was filling from empty, just after his 227mile run. His D2 auto at 38mpg equals my evoque at the moment for combined mpg!

[CJ1]

No, I wasn't filling it from empty. Please re-read what I wrote. I had a full tank and then did the mileage, and then filled it to the brim after that mileage. 272 miles put the needle from above the full white line to just above the 3 quarters line. I then filled it again from 3 quarted of a tank. It cost me £42 of diesel to approc a quarter of a tank of diesel. I tell you now. If I got 272 miles out of 1 tank of diesel, This Disco would have gone in the ditch on purpose lol

I am getting around 37-38mpg on a run after giving a damn good run with various speeds and using Wynns diesel treatment stuff. I put the same stuff in my Vectra to and it has made one hell of a difference to how the Vectra behaves too.

I think I must have had some carp in the fuel system as it also feels a little more powerful too.

[Scotts90]

Must be a good one...my 12 plate AWD transit, which is fully laden (3500kg with me in it at last weigh-in) averages 36mpg. It's "twin" which is a good deal lighter only does 26....so it can happen. Driving style has a lot do do with it too.

[Anderzander]

Land Rover's R&D department will be in touch shortly - they want to look at your car ...

[CJ1]

Also depends on the roads used too. I am in a mostly flat area.

[CJ1]

I am not the only one getting good MPG out of my TD5, there are other people who have replied to this post saying they are getting good MPG too. It is down to condition of the vehicle's mechanicals and driving style and conditions.

[Shackleton]

almost choked the first time I filled it up from empty

The long range tanks mine came with mean that at current prices it'd be €230 a fill. I'd probably make it a few miles from the service station on the spontaneous combustion of my wallet alone

Land Rover's R&D department will be in touch shortly - they want to look at your car ...

Wish they'd come look at mine, I'd tell them a thing or two.

I am not the only one getting good MPG out of my TD5, there are other people who have replied to this post saying they are getting good MPG too.

I think I'm one of them. Hey I don't want to come across like I'm on the offensive. Far from it, I'm intrigued and would love to be able to quantify what's going on. If I can satisfy my curiosity and prove you right then I can try and emulate the conditions your car operates in. I'm just of the opinion that even if it's a 'good one', I don't think it'd be quite that far ahead of the average figures. May I ask if you've noticed whether they make the same speeds at the same rpm? And do they log the same distance on the odometer for a given A to B?

[CJ1]

The miles from a to b are the same as the journeys I do are very repetitive and being doing them for 3 years in many different cars, The speeds according to my Sat Nav are reading the same, My nav always told me on the last Disco that I was going 3mph less than the speedo appeared to read and that is the same with this one. They are both ES models and auto's with 7 seats, both had towbars, nudge bar, but this one doesn't have side steps yet. The journeys I do when I get the best MPG reading is using cruise and barely a hill in site. Only very slight inclines but all fast roads.

I am not usually heavy footed. I rarely have more than 1 passenger, I keep my window open a bit at low speeds and shut above 40mph, I have wind deflectors, And I maintain steady speeds most of the time. Obviously when I was towing my mpg figures weren't as good. And I must add, the weather conditions have been good too. My Discovery doesn't smoke at all, neither did the last one, And I mainly use 1 company for fuel. (Tesco), I never use Shell as they are expensive and rarely use Jet but so on occasion, and Sainsbury's is another company I use but as little as possible.

The tyres are all 36psi during the summer on all my 4x4's and 34psi in Winter. And I use the gears to slow down and avoid using the brakes. I also normally make sure that I only have what I need in the car. I haven't towed with my current Disco yet so not sure on mpg figures on that side of things yet.

[CwazyWabbit]

It's probably mostly down to your driving style and the flat roads you are using, have a read up on hypermiling .... you might be able to get even more out of a gallon

[CwazyWabbit]

......

I think I'm one of them. Hey I don't want to come across like I'm on the offensive. Far from it, I'm intrigued and would love to be able to quantify what's going on. If I can satisfy my curiosity and prove you right then I can try and emulate the conditions your car operates in. I'm just of the opinion that even if it's a 'good one', I don't think it'd be quite that far ahead of the average figures. May I ask if you've noticed whether they make the same speeds at the same rpm? And do they log the same distance on the odometer for a given A to B?

There aren't any flat roads in Ireland, it's all hills so you have no chance of matching CJ1

[CJ1]

It's probably mostly down to your driving style and the flat roads you are using, have a read up on hypermiling .... you might be able to get even more out of a gallon

I have never heard of that term before. But I have always got good MPG out of my cars. I have since reading your reply look it up on Wikipedia, I won't be doing half of that carp.

Although it did make me realise that there is another thing I do on Motorways. As long as the fast lane is clear, If I see a large lorry ahead of me I will where possible and without holding other people up get into the fast lane to get as far from them as possible, but that is more to do with an accident I was in many years ago where I was driving up the middle lane overtaking a foreign lorry and he pulled into the side of me and flipped me on to the opposite carriage way into on coming traffic. So I am a lot more weary of lorries. Although I am not saying I am a perfect driver! As I don't do all this all the time. But do most of the time.

[CwazyWabbit]

Lol, some of the stuff does seem like a good way to spoil your enjoyment of a drive

[deep]

I'm always curious when someone reports decent fuel economy and others are very disbelieving. A modern turbo diesel like a TD5 should be very efficient. There are still laws of physics. To get the most of that efficiency requires taking the lead out of your shoes and driving with some understanding, along with conditions which allow a minimum of speed changes. It's not rocket science (rockets are hard to drive economically...).

I'm reminded of when I was crossing Australia via the desert routes in a 1982 3.5 Range Rover. At the constant, quite low speed I was doing, I consistently got 20 m.p.g.. A few people struggled to believe that. These people generally drove big diesel Land Cruisers and only got around 17 m.p.g.. Yet I met a few folk in TDi Discoverys who reported getting 35 m.p.g.. It strikes me that the difference was less to do with the inherent efficiency of the vehicles (though that clearly exists) than the whole attitude of the driver. The people in the big 'Cruisers were laden to the gills with masses of gear and drove like they had to cross the desert that day. The Discovery drivers, like myself, carried what they needed and no more and drove much more cautiously.

Anyway, I am pleased the poor economy problem in this case has been sorted. Particularly as I am seriously hoping to get a TD5 in the next few months!

[Anderzander]

My cheekiness aside .....

I'm just of the opinion that even if it's a 'good one', I don't think it'd be quite that far ahead of the average figures.

.... This is sort of where I am. It's the order of magnitude - and the common denominator is of course CJ, so it does point to driving style.

But to put some figures around it - where LR are citing maximum efficiency for that model at 30 mpg, and manufacturers figures are usually generous, then 38 mpg is 127% of that figure.

I think there are folk on the forum who could confirm I drive 'sedately' and I certainly drive sympatheticly to the engine and running gear..... But I don't get close to a 26% increase on the stated maximum for my vehicle.

So its not that I don't believe it - just that its hard to believe !

[Shackleton]

What you guys said. My driving for economy is bordering on obsession. Hypermiling as a thing is news to me, but I drive from instinct using some of those techniques. I coast downhill because to my mind 'pulling' a vehicle downhill when gravity will do it for free is just wasteful. My D2 only ever revs to 2250rpm (or whatever) to get the upshift. As in I'll hold up traffic while waiting for the autobox to use a constant throttle of 2000rpm to get me up to speed. (it does get the odd blast to keep everything clear). I take routes home that have less undulations/junctions so that my throttle stays as constant as possible. And generally I drive slow. On the motorway I'll usually be at about 67mph, just enough to pass an artic in good time. My car's fuelling systems are well serviced and as Deep said I keep everything free of unnecessary weight. I've a pain in my neck keeping tyre pressures checked.

And even with all that, I consider myself incredibly lucky to receive 6% over Land Rover's figures. And thats extra urban. I've realised that most of the time it seems to be returning in the order of 15% below. I'm fairly sure I was getting in the order of 35mpg in my Td5 manual RR on the motorway, but that's a strange mechanical concoction, and very light by the standards of what the Td5 usually has to haul. So yeah, Zander's cheekiness aside (lol)... it's not that I don't believe, I just can't believe. But I really want to.

I'd love to know how you drive CJ, and how you make your calculations, and the various figures from a computer plugged into your car. Cause I want 38mg! If I had 38mpg coming from my LR's I could break my best mates silly Saab obsession. He'd come over to the mucky side in blink of a Jedi's eye.

[reb78]

The other thing here might be that, on my D2 at least, filling to the second click of the pump is not really 'brimming' the tank, nor will it be consistent in terms of measuring volume of fuel used. After the second click, if i go carefully, i can get ~ 15 litres (so around 3 gallons) of extra fuel in before it is actually brimmed. Given that some pumps froth the diesel more than others (sometimes the same pump), i would think that measuring and filling to the second click isn't that accurate really.

[V8 Freak]

I keep track of every tank in my TD5 90 (An old habit from the 4.6 that stopped me from driving it too often and bankrupting me..) and I average 27MPG for the last 55k miles.

My ODO is near bang on with GPS thanks to taller tyres (255/85) that take out the 5% error that existed.

Generally I get approx. 27 MPG from each tank.

I am not the most frugal of drivers and typically travel most long journeys at 70mph, with the Overdrive engaged.

When I take the time and focus on what I'm doing, amble along at 55 ish I can get up to 32MPG, but no higher.

Interestingly, I still get the same MPG returns now with a bigger intercooler, VGT and remap from IRB compared to standard, albeit the performance is incredibly different to standard.

I am confident my engine and running gear are in good order, all regularly serviced and oils changed to recommendations.

When I use Cruise Control my MPG drops.... I think this is largely because the ECU tries to maintain the speed regardless on inclines and accelerates as hard as it can to get up to a speed when I resume use. That said, If I am on a long journey I typically use CC for consistency and know what I'm doing to the economy.

A friend does have a D2 Auto and on recent long journey reports 33 MPG, but I don't know how accurate his ODO reads.

I struggle to comprehend 38 MPG, even in a D2 with is more streamlined body compared to my 90, based on my own experiences.....

Neil

[AMB]

I'm with Anderzander, - "its not that I don't believe it - just that its hard to believe !"

[honitonhobbit]

I get 30+ out of my D2 Td5 but it's had it's auto-box re-mapped to match it's re-chip; and I drive steadily. The Wife can't get more than 28 form the same motor. I reckon I could get it up to about 33 on the motorway

My 300Tdi Auto does 31+ on pretty much any journey

My 200Tdi Manual has seen almost 40mpg but tends to be about 35

My Skoda Roomster Scout 1.6Tdi does about 63mpg when driven about as uneconomically as possible

[Shackleton]

it's had it's auto-box re-mapped to match it's re-chip;

I'll have some of that! Who did the work, what did it cost and what are your power figures now?

[deep]

I get 30+ out of my D2 Td5 but it's had it's auto-box re-mapped to match it's re-chip; and I drive steadily. The Wife can't get more than 28 form the same motor. I reckon I could get it up to about 33 on the motorway

My 300Tdi Auto does 31+ on pretty much any journey

My 200Tdi Manual has seen almost 40mpg but tends to be about 35

My Skoda Roomster Scout 1.6Tdi does about 63mpg when driven about as uneconomically as possible

I had an Austin Metro "Mayfair" which regularly got 62 m.p.g. on a run. Out of a petrol engine! I still wonder how they managed that! A Mini 1000 I had earlier used to get around 45 m.p.g. on the same runs...