306 TD fuel consumption.
Moderator: RichardW
306 TD fuel consumption.
I'll admit to having a heavy right foot, but on my last tank I got 34mpg out of my 306 TD. Its '96 N-reg with 120k miles and full service history. The fuel consumption has been dropping of late. I know its due for an oil change right now, when I'll also change the fuel and air filter, but is there anything else that might want looking at? (Besides me cruising at 90mph). Even at 70-75mph on the M1 the other week it only hit 40mpg, so somethings not right unless everyone else tells fibs about their fuel consumption of their 306's.
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woodhead722
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From my experience it all depends on how you drive. In the days when I had the use of company car, I used a 306dt for a couple of weeks. Around town the mpg would be excellent. However a soon as I got the open road and started using the turbo, the economy tumbled, being only a couple of mpg better than my 2.0 petrol. After I had the car the new keeper was more sedate driver and the overall mpg figure for the car showed an increase.
People who say they get over 50 or over 60 are fooling themselves. A friend who creeps round in his dt only averages 46 mpg.
My conclusion is that, if you're a 'press on driver' then a petrol engine is a better option.
Paul.
People who say they get over 50 or over 60 are fooling themselves. A friend who creeps round in his dt only averages 46 mpg.
My conclusion is that, if you're a 'press on driver' then a petrol engine is a better option.
Paul.
I've got it sorted now. I was using BP Ultimate Diesel to see if is made any difference. I can report that it did, it destroyed my fuel economy. I've used half a tank of normal diesel this week, after 1 month of Ultimate and falling fuel economy. On Ultimate I've averaged for the month 37 mpg. Now I'm back on ordinary, I'm straight back up to 40-42mpg, and that's driving through the centre of London or doing 90mph on the M25, which is all I have been doing this week.
One thought on the economy subject, the more you use the turbo, the more air is entering the engine and more fuel is used.
So in theory, is when you are accelerating through the gears try to keep the engine around the peak torque (2250 rpm) as this is when the motor is most fuel efficient. The turbo comes into life at 1500 and reaches maximum pressure at 3000rpm. It is pointless to take the engine above that point as you are causing undue wear and wasting fuel.
Have a try at this theory. I first tried this out during the fuel crisis (remeber that!) and increased the ecomony from 50 to 58 mpg on an astra 1.7tdi (isuzu engined)
Good luck
So in theory, is when you are accelerating through the gears try to keep the engine around the peak torque (2250 rpm) as this is when the motor is most fuel efficient. The turbo comes into life at 1500 and reaches maximum pressure at 3000rpm. It is pointless to take the engine above that point as you are causing undue wear and wasting fuel.
Have a try at this theory. I first tried this out during the fuel crisis (remeber that!) and increased the ecomony from 50 to 58 mpg on an astra 1.7tdi (isuzu engined)
Good luck
The car is most fuel efficient at 56mph in top gear, which is about 2000 rpm.
The trick is to get the car as quickly and efficiently up to this speed ( lets say 60mph ), and keep it there.
By quickly, I do mean good acceleration, using all the fuel available, but the key is to NOT WASTE FUEL. Black smoke out the back is unburned diesel, hence waste.
I have managed to get consistently high figures out of my 405, with a full boot, and racing the boy racers off the traffic lights, simply by being smooth but progressive with the accelerator cable, and looking ahead at traffic conditions.
For the record, I do approx 90 miles per day, 20 of which are urban, the rest on the M1.
The trick is to get the car as quickly and efficiently up to this speed ( lets say 60mph ), and keep it there.
By quickly, I do mean good acceleration, using all the fuel available, but the key is to NOT WASTE FUEL. Black smoke out the back is unburned diesel, hence waste.
I have managed to get consistently high figures out of my 405, with a full boot, and racing the boy racers off the traffic lights, simply by being smooth but progressive with the accelerator cable, and looking ahead at traffic conditions.
For the record, I do approx 90 miles per day, 20 of which are urban, the rest on the M1.
Hiya
Bit late replying to this topic, but I found the same exact thing with my 405Tdi, Bosch pump.
Running 100 miles a day, with 50 miles being fast motorway, 25 being slow a-road, and 25 being fast unclassifieds and moor roads.
I ran normal BP diesel, and usually got 39-42mpg, even when going at 85mph ish on the motorway. I run mine turned up a bit on the pump, but no more boost.
For the last 3 tanks, with BP Ultimate and with some Reddex to give the pipes a clean, I have been getting 36 ish mpg, which is quite honestly awful. I don't know if it just burns more somehow, or whether I'm driving harder, but that kinda mpg, along with the fuel costing a fair bit more is really poor.
I did once try to see how much I could get from a tank, and I cruised at 60 all the time (hard when a turned up pump gives so much more top end right upto 100mph), but I managed it for a whole week, and got just over 500 miles from a tank, 80 more than usual. Going from 40mpg average to nearly 48mpg.
I really think it is the high speed cruising that does it, even at 80mph, your right at 3000rpm, using loads of fuel. A 6 speed box with another gear on the end for cruising is what you need, just like modern diesels. I bet thats why they can get such huge mpg's (along with better general consumption anwyay)...
Can't wait to cut my commute to 100 miles a week... ahhhh, the fuel tax savings alone will pay for half my mortgage
Seya
Dave
Bit late replying to this topic, but I found the same exact thing with my 405Tdi, Bosch pump.
Running 100 miles a day, with 50 miles being fast motorway, 25 being slow a-road, and 25 being fast unclassifieds and moor roads.
I ran normal BP diesel, and usually got 39-42mpg, even when going at 85mph ish on the motorway. I run mine turned up a bit on the pump, but no more boost.
For the last 3 tanks, with BP Ultimate and with some Reddex to give the pipes a clean, I have been getting 36 ish mpg, which is quite honestly awful. I don't know if it just burns more somehow, or whether I'm driving harder, but that kinda mpg, along with the fuel costing a fair bit more is really poor.
I did once try to see how much I could get from a tank, and I cruised at 60 all the time (hard when a turned up pump gives so much more top end right upto 100mph), but I managed it for a whole week, and got just over 500 miles from a tank, 80 more than usual. Going from 40mpg average to nearly 48mpg.
I really think it is the high speed cruising that does it, even at 80mph, your right at 3000rpm, using loads of fuel. A 6 speed box with another gear on the end for cruising is what you need, just like modern diesels. I bet thats why they can get such huge mpg's (along with better general consumption anwyay)...
Can't wait to cut my commute to 100 miles a week... ahhhh, the fuel tax savings alone will pay for half my mortgage
Seya
Dave
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philhoward
I'd say the HDI is a much better option if your after efficiency and have some money to spend. A friend at work hard one and it got 55 mpg all the time, and he drove like me, who gets 40 mpg!
However, if your car is simply a run about, don't bother. After depreciation on a nice Hdi Dturbo 306, and the cost of actually buying it and saving in insurance etc, it'd take about 8 years to break even on owning it, and thats 24000 miles a year And he's just rid of his as it was quite unreliable, catalytic converter problems expensive, egr, sensors and all that!
Still, it's nice to splash out, maybe a golf tdi?
The new 1.5 Hdi 110 sounds nice too!!!
Seya
Dave
However, if your car is simply a run about, don't bother. After depreciation on a nice Hdi Dturbo 306, and the cost of actually buying it and saving in insurance etc, it'd take about 8 years to break even on owning it, and thats 24000 miles a year
And he's just rid of his as it was quite unreliable, catalytic converter problems expensive, egr, sensors and all that!Still, it's nice to splash out, maybe a golf tdi?
The new 1.5 Hdi 110 sounds nice too!!!
Seya
Dave