Low MPG

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Mastiff
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Low MPG

Post by Mastiff »

In need of some help here.

My 2000 110 HDI is returning around 35mpg. This is a bit of town, country and motorway driving. She was returning around 46mpg when I first got her in May. I gave her a full service around 2,000 miles ago. Any ideas or is this figure about right for this time of year........Also she normally always has my 10st Bullmastiff in the boot which may make a bit of difference?
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steve_earwig
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Re: Low MPG

Post by steve_earwig »

That does seem a bit crap. I can't think 10st would make that much difference (~1 large wife) Check for seizing brakes, that sort of stuff.
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highlander
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Re: Low MPG

Post by highlander »

Tyre pressure - with the drop in temperatures, the air pressure in your tyre will also vary (physics, etc).

Under-inflated tyres can have a significant impact on fuel economy, not to mention safety and tyre wear.
2002 (D9) Peugeot 406 Coupe SE, 2.2 litre Petrol. Scarlet Red/Rouge Ecarlate/Rosso Scarlatto. Black Leather interior. SOLD :(
2008 (E60 LCI) BMW 525i M-Sport, 3.0 litre Petrol. Carbonschwarz Metallic. Black Dakota Leather and Myrtlewood interior.
Mastiff
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Re: Low MPG

Post by Mastiff »

Thanks guys.

Will check my tyres. I think they are meant to be around 34psi?
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highlander
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Re: Low MPG

Post by highlander »

That's right.

If you open the drivers' door and look at the A pillar, there should be a sticker showing things like the correct tyre sizes, pressure, the paint code, etc. It's really useful!
2002 (D9) Peugeot 406 Coupe SE, 2.2 litre Petrol. Scarlet Red/Rouge Ecarlate/Rosso Scarlatto. Black Leather interior. SOLD :(
2008 (E60 LCI) BMW 525i M-Sport, 3.0 litre Petrol. Carbonschwarz Metallic. Black Dakota Leather and Myrtlewood interior.
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steve_earwig
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Re: Low MPG

Post by steve_earwig »

Unless your car's had a prang and it's been removed...
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Mastiff
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Re: Low MPG

Post by Mastiff »

Alrighty then!!

Tyre pressures are all 34psi. Air filter nice and clean, oil fine etc.......But still been returning 35mpg? Can you reset the ECU on 406 HDI's by leaving the positive battery lead off for 30 mins? I remember with a lot of my old hot hatches that was always the way but don't know about latest diesel engines? The other thing it sometimes does is make a buzzing kind of noise for say 5 seconds when I turn the ignition on, most prob' the fuel pump but this buzzing keeps on going even after the car is turned off for say 20 seconds?

Also.......I may sound a bit thick here!! But how do I find out if my brakes are binding?
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steve_earwig
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Re: Low MPG

Post by steve_earwig »

Jack each corner up & spin the wheel.

Not sure if disconnecting the battery does anything on these.

The buzzing after you kill it is (I think) the vacuum in the brakes/servos dissipating. Try pumping the brakes a few times.
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totaleclipse
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Re: Low MPG

Post by totaleclipse »

Mastiff wrote: but this buzzing keeps on going even after the car is turned off for say 20 seconds?
mine sounds like a jet engine turning off.

turns out its the radiator fans being noisy.
1997 2.1TD executive estate - mmmm, lovely :)
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