ndamico Posted March 29, 2020 Share Posted March 29, 2020 Hoping for some help. Have 200kms on it. Seems to run great but get about 16mpg max. I'm new to the td5 so here is how its setup, some of which I know doesnt help mileage. I dont have a fast tune in it and dont hot rod the car. It's an overland vehicle so lots of trails and freeway stuff getting there. I usually run 70MPH on the freeway. Any reason why the mileage is so poor? Stock gears with Ashcroft lockers 1.4 tcase 35x12.50r17 maxxis razr MT Exocage 2" lift Ashcroft underdrive BAS intercooler MANN pro vent Turbo technics VGT from BAS Storm tuning Egr removed Cat removed Stainless exhaust 82*C thermostat Nanocom New fuel pump New alternator New silicone coolant hoses New pressure regulator new alternator New injector harness new water pump Quote Link to comment Share on other sites More sharing options...
Eightpot Posted March 29, 2020 Share Posted March 29, 2020 70 mph in a Defender on big MT tyres with an exterior cage in a chipped TD5 will not be economical on fuel. You've built a rock crawler not a long-distance tourer. 2 Quote Link to comment Share on other sites More sharing options...
Anderzander Posted March 29, 2020 Share Posted March 29, 2020 That’s true - but I’m getting 30. I wonder if your map is throwing fuel at it.. ? Quote Link to comment Share on other sites More sharing options...
Anderzander Posted March 29, 2020 Share Posted March 29, 2020 Assuming it’s standard Td5 gearing (gearbox and diffs) you should be doing about 2600 revs at 70mph - which seems comparable to a Td5 with smaller tyres and a 1.2 transfer box. If you drive at 60mph what mpg are you getting. Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted March 29, 2020 Share Posted March 29, 2020 The difference between 60-65 mph on the motorway and 70 mph robs me of about 2-3 mpg. Wind resistance is the killer. Add on the silly big/knobbly tyres, lift, remap, extra weight and you’ll easily see sub-20 mpg. I see also you’re in the US - 16 of your MPGs is just over 19 of ours, so bear that in mind when comparing with figures from the UK. 2 Quote Link to comment Share on other sites More sharing options...
Chicken Drumstick Posted March 29, 2020 Share Posted March 29, 2020 3 hours ago, ndamico said: Hoping for some help. Have 200kms on it. Seems to run great but get about 16mpg max. I'm new to the td5 so here is how its setup, some of which I know doesnt help mileage. I dont have a fast tune in it and dont hot rod the car. It's an overland vehicle so lots of trails and freeway stuff getting there. I usually run 70MPH on the freeway. Any reason why the mileage is so poor? You're in CA but using KM's? Is that US gallons or Imperial for the mpg? How are you actually working this out? Either way it seems low. Have you checked for fuel leaks? Quote Link to comment Share on other sites More sharing options...
Eightpot Posted March 30, 2020 Share Posted March 30, 2020 As said, that's equivalent to about 20mpg imperial - if thats an average over your fast road and off road fun you probably aren't seeing anything too unusual for a presumably heavy TD5 with a cage. Drop your speed down to 65 and you should see a difference. Running sub 28/40 psi tyre pressures front/rear with big MTs will knock a few mpg off also. Diesel is significantly cheaper in the US so I guess you're not so used to stretching a gallon out as we are here? Quote Link to comment Share on other sites More sharing options...
landroversforever Posted March 30, 2020 Share Posted March 30, 2020 How are you calculating it? Brim to brim with with tank? Quote Link to comment Share on other sites More sharing options...
Tanuki Posted March 30, 2020 Share Posted March 30, 2020 Given the load you're lugging, paradoxically you may find you get better 'highway' mileage from driving in 4th rather than 5th. An engine spinning freely at relatively-high RPM can be more thermally-efficient than one 'labouring' against a large load at low-revs. And, mechanically, the gearbox in 4th is 'straight through' with minimal friction whereas in 5th the intermediate-shaft is involved, which must mean extra power-wasting drag. In my 90TD5 even when running 'light' I don't ever use 5th below 55MPH. The TD5 has BMW heritage - designed to rev! Quote Link to comment Share on other sites More sharing options...
landroversforever Posted March 30, 2020 Share Posted March 30, 2020 The TD5 doesn’t have any BMW heritage, it was designed before BMW took over. 1 Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 31, 2020 Share Posted March 31, 2020 16(US) MPG, wow, if you fit a V8 you MPG will probably go up! Quote Link to comment Share on other sites More sharing options...
Chicken Drumstick Posted March 31, 2020 Share Posted March 31, 2020 On 3/30/2020 at 5:57 PM, Tanuki said: Given the load you're lugging, paradoxically you may find you get better 'highway' mileage from driving in 4th rather than 5th. An engine spinning freely at relatively-high RPM can be more thermally-efficient than one 'labouring' against a large load at low-revs. And, mechanically, the gearbox in 4th is 'straight through' with minimal friction whereas in 5th the intermediate-shaft is involved, which must mean extra power-wasting drag. In my 90TD5 even when running 'light' I don't ever use 5th below 55MPH. The TD5 has BMW heritage - designed to rev! They said running at 70. You won’t be doing that in 4th!! Td5 has as much to do with BMW as Ferrari does. 1 Quote Link to comment Share on other sites More sharing options...
Chicken Drumstick Posted March 31, 2020 Share Posted March 31, 2020 On 3/30/2020 at 12:30 PM, Eightpot said: As said, that's equivalent to about 20mpg imperial - if thats an average over your fast road and off road fun you probably aren't seeing anything too unusual for a presumably heavy TD5 with a cage. Drop your speed down to 65 and you should see a difference. Running sub 28/40 psi tyre pressures front/rear with big MTs will knock a few mpg off also. Diesel is significantly cheaper in the US so I guess you're not so used to stretching a gallon out as we are here? 20mpg imperial from that setup as a mean average and not thrashing it. There is something not right at all. Fuel leak, poor map or calculating it and distance incorrectly. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 31, 2020 Share Posted March 31, 2020 I wonder about the mapping/performance upgrades, a lot of them just wind the fuel up or do awful bodges like fudging the air/coolant temperature sensor values to the ECU to make it throw more fuel in. If black smoke is coming out you're wasting fuel. 1 Quote Link to comment Share on other sites More sharing options...
Anderzander Posted March 31, 2020 Share Posted March 31, 2020 Thus my comment above pondering if the map was just chucking fuel in to for power - I wonder if it smokes? I wonder if the FPR is leaking? Quote Link to comment Share on other sites More sharing options...
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