HDI more MPG

[KevinTW]

My mileage is 18k a year about 60% town 40% motorway. I get 43 mpg but want more. My car has aircon that doesn't work and a cat. I have a K and N filter in the air box. Can I pull off the aircon pump and change the belt? If I decat it what difference will that make? Does anybody do a remap for mpg? I don't mind losing a bit of bhp. The car has done 142k and burns no oil. 1.36 on the smoke test.I would really welcome a bit of advice.

[Midnightclub]

De-cat would probably help the turbo spool maybe a few hundred rpm earlier, that'd help slightly with economy. A decent service too will probably bring that number up slightly.. Removing the aircon pump won't do a massive amount as there'll be barely any drag unless the A/C clutch is engaged.. Another thing to do, check for any boost leaks (they're easy to miss if you've not got an intercooler) usual culprit is the small rubber turbo pipe directly off the turbo, run some water with a bit of washing up liquid over any boost pipes and they'll soon start to bubble if there is

[Tyronnster]

Think you will need the rallaye belt setup to remove the ac pump

[Midnightclub]

You don't run the rallye setup, you just use a shorter belt (6***PK iirc??)

[Toms306]

6pk1162 or something like that iirc.

That mpg really is poor though, I wouldn't be surprised if the egr valve is leaking so might be worth blanking that.

And also a stage 1 remap gives more mpg and power, 90bhp just isn't enough to pull an estate efficiently imo.

[Midnightclub]

Sounds right tom

Good shout, knew i'd forgotten something! Definitely blank the EGR.

Fairly poor though, mrs stage 2 always averages around 50-55mpg

[cully]

43mpg on an Estate is about right i get between 42-45 on mine with a st 1 map calculated over a tankful of fuel
the EGR valve on these kills MPG if you physically blank it off you should see gains

http://www.fuelly.com/driver/cully/306

[Toms306]

But you obviously have a lead foot!

I ragged my China estate and moved an entire cottage worth of stuff in a month and stilll didn't get below 45mpg! Tbh I was annoyed if it did below 50!

[cully]

But you obviously have a lead foot!

umm yes!

and your point is?
i do hope your not discriminating against my disability

[Eeyore]

service, decat and stage 1

[KevinTW]

6pk1162 or something like that iirc.

That mpg really is poor though, I wouldn't be surprised if the egr valve is leaking so might be worth blanking that.

And also a stage 1 remap gives more mpg and power, 90bhp just isn't enough to pull an estate efficiently imo.

Could anyone send a pic with a big arrow showing where the blank goes. I have tried to find one on Ebay with no success. If anyone has an item number that would be great. Really appreciate all the help.

[Ruan]

No need to bypass the AC pump - it's really not doing any harm since it's clutched, for the hassle it's not worth trying to get a belt that fits.

[cully]

Could anyone send a pic with a big arrow showing where the blank goes. I have tried to find one on Ebay with no success. If anyone has an item number that would be great. Really appreciate all the help.

http://306oc.co.uk/forum/thread-13047.html?

[KevinTW]

No need to bypass the AC pump - it's really not doing any harm since it's clutched, for the hassle it's not worth trying to get a belt that fits.

Thank you. The aircon light comes on sometimes. Is there a fuse I can pull or does the light make no odds. I looked at diagrams of the belt layout for non aircon and it is very different.

[cully]

the light will come on,on the aircon system even though it wont work
there is a pressure switch in the gas line that switch's off the compressor to protect the bearings in the pump if the system has no gas

[gareth7]

If you do want to remove the aircon the belt you need is a 6PK1175

[rd070707]

check for any boost leaks (they're easy to miss if you've not got an intercooler) usual culprit is the small rubber turbo pipe directly off the turbo

i noticed when i was under mine last week that the rubber pipe that comes of the turbo had oil/ gunk over it. boost leak?

[Poodle]

How long have you been running the k&n? It's probably eaten your maf, that'll knock a good chunk of your mpg, see if one of the local garages can check its wrking for you.

[Midnightclub]

check for any boost leaks (they're easy to miss if you've not got an intercooler) usual culprit is the small rubber turbo pipe directly off the turbo

i noticed when i was under mine last week that the rubber pipe that comes of the turbo had oil/ gunk over it. boost leak?

Sounds like it to me, mine was plastered in oil! Ended up having about an inch split through it

[KevinTW]

You know what. I liked my non turbo 1.9 XUD 405 estate much better. Nothing to go wrong and I could put 20 bags of cement in the back without it sitting on its arse! I got 43mpg out of that all the time and it passed the emissions with ease.

[KevinTW]

Could anyone send a pic with a big arrow showing where the blank goes. I have tried to find one on Ebay with no success. If anyone has an item number that would be great. Really appreciate all the help.

http://306oc.co.uk/forum/thread-13047.html?

Mine does not have the douser. Can you label the pipe I need to block off with a bolt and jubilee clip? Is that really all I need to do?

[Dum-Dum]

Right a few things.

My driving is pretty similar to yours in terms of being 60% motorway and im averaging 45mpg over 3500miles http://www.spritmonitor.de/en/detail/583387.html

A stage 1 map will increase your power but will also increase your economy.
A straight through back box, de cat and EGR blank (blank it properly in case its leaking) will also help.

The real best way of improving economy is narrower tyres. Swapping from 185 wide to 205 wide saw about a 20% drop in my MPG on the scan guage.

If you want to go really extreme stripping the interior out the car can give 5-10% better MPG

[Toms306]

You know what. I liked my non turbo 1.9 XUD 405 estate much better. Nothing to go wrong and I could put 20 bags of cement in the back without it sitting on its arse! I got 43mpg out of that all the time and it passed the emissions with ease.

Non turbo and you only got 43mpg? Wow, maybe the HDi isn't so bad then!!

The smoke test fail was nothing to do with the engine itslef, it was that daft chip.


For the EGR valve, you want to add the blank as well. Unplugging it is fine if the system is working, but if the EGR is already leaking, unplugging wont make a difference, you need to add a blank where it meets the inlet pipe for best effect.

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The real best way of improving economy is narrower tyres. Swapping from 185 wide to 205 wide saw about a 20% drop in my MPG on the scan guage.

This is a good point, not just the size, but the tyre type as well. Proxes and rainsports both lost me a few mpg over things like P6000s and Goodyear NCT 5s. But personally I'd rather have grip than an extra few MPG though lol.

[vlj]

If you want to go really extreme stripping the interior out the car can give 5-10% better MPG

Is that because the car is 5-10% lighter?

[KevinTW]

Right a few things.
205 tyres are wider than 185!
My driving is pretty similar to yours in terms of being 60% motorway and im averaging 45mpg over 3500miles http://www.spritmonitor.de/en/detail/583387.html

A stage 1 map will increase your power but will also increase your economy.
A straight through back box, de cat and EGR blank (blank it properly in case its leaking) will also help.

The real best way of improving economy is narrower tyres. Swapping from 185 wide to 205 wide saw about a 20% drop in my MPG on the scan guage.

If you want to go really extreme stripping the interior out the car can give 5-10% better MPG

[Jonny81191]

If you want to go really extreme stripping the interior out the car can give 5-10% better MPG

Is that because the car is 5-10% lighter?

[Poodle]

Lol read the sentence again dude, he says he saw a drop in mpg.

Pro_steve did some experimenting with economy maps, might be worth contacting: www.hdi-tuning.co.uk. I saw a 10% rise in my mpg from one of his economy maps, but i saw the same gain with his normal stage 1 map, so long as i didn't use the power anyway lol.

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You know what, just look at my project thread lol, link in my sig down there VVV. Loads of ideas in there - longer gearbox from a 206 eco (rare as hens' teeth, unfortunately); lowering the car (genuinely helps); undertrays, full or partial; etc etc.

[KevinTW]

Lol read the sentence again dude, he says he saw a drop in mpg.

Pro_steve did some experimenting with economy maps, might be worth contacting: www.hdi-tuning.co.uk. I saw a 10% rise in my mpg from one of his economy maps, but i saw the same gain with his normal stage 1 map, so long as i didn't use the power anyway lol.

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You know what, just look at my project thread lol, link in my sig down there VVV. Loads of ideas in there - longer gearbox from a 206 eco (rare as hens' teeth, unfortunately); lowering the car (genuinely helps); undertrays, full or partial; etc etc.

Cheers for all of this, I really appreciate the input.Keep it coming. My daughter plays for 3 football teams, that mileage added to my stop start work mileage and we spend more on diesel than we do on groceries. Girls' footie is a nightmare as the teams are miles away.
The wide tyre thing is totally true. Cars today all have 185 tyres as a minimum and when I started driving it was only 2.0 capris,XR2/XR3 Golf GTI etc that had them. If cars were as light as that now with skinny 155 tyres the new engine technology would mean every car would do 80mpg. Put road tyres on a mountain bike and you'll soon see.

[Dum-Dum]

Yeah I reckon a 106 nad with a 1.4 hdi would do close on 100mpg on a run especially with some proper eco mods

[Poodle]

Should do easily, I still reckon I can pass 80mpg with the 306 without getting too extreme. Kezzie has got me beat with something like 73 atm, but i'll get him.