Hooray for cooking oil

MikeT · Post by **MikeT** » 06 Jul 2007, 18:00

My Granada 2.0i petrol engine astounded me when I realised it would return on average, 9-10 miles per £1 for normal (unleaded unless I hammered it of course). All of this for urban driving by the way.

So you can imagine my anticipation of better consumption when I took posession of a Citroen 1.9 diesel last month!

Initially, the figures look disappointing but I haven't done a concise calculation yet. For instance, the last refill of 19.54 litres ( I usually top up when the fuel light comes on continuously for more than 5 miles) has returned only 150 miles and the previous refills averaged about the same - £5 giving 42 miles, £10=84 etc.

Additionally, I had high expecations of the "Turbo" aspect of this engine - only to be disappointed again.

[Oh, and one more criticism that annoys me at each refill - especially given that diesel engines suffer heavily from water contamination - is why does water collect inside the petrol cavity behind the filler flap????
There is no drain hole. Yet after enough rain, there is a puddle of water just below the filler neck, indicating it runs off somewhere if higher.
If I don't remove that water first, it's easy splash it water into the filler neck when refuelling. First time I noticed the water was when surface tension wicked it up the filler nozzle and over? the lip of the neck]

BUT...

The truly redeeming factor of this car (and it's just as well!) is it's ability to be fuelled with pure vegetable oil - the cheapest of the cooking oils - with no modifications whatsoever (unless it's very cold due to the viscosity of oil - which brings other problems that need to be considered as well as the legal aspects).

I've read a lot about this topic and one claimed fact I'd like to believe (have yet to confirm it) is that cooking exhaust gases are less polluting and contains no carcinogens?

It smells like a chip shop but I see that as another positive compared to the smell of diesel exhaust. Although I've yet to check the (new) fuel filter for contamination, I've read that cooking oil is also a natural fuel system cleaning agent.

So while experimenting, today I ran with maybe 75-80% cooking oil and it might be my imagination but the power seems improved a little.

I'll be reading about purifying used oil next if all goes well. Wherever next ..Jet engines anyone?

Xaccers · Post by **Xaccers** » 06 Jul 2007, 18:36

Pretty sure my Xantia's had drain holes but they do get lots of dirt around there which blocks it up. Will double check in a bit.

SVO is known as a carbon neutral fuel (although it's not quite because of the CO2 released in growing and harvesting the crop and converting it to oil) as the CO2 released by burning the oil is the same CO2 absorbed by the plants as they grew (although you don't burn all the plant so perhaps it is CO2 neutral after all).
The other nasties you get from diesel are pretty much the same from SVO from what I've read.
Using just 10% SVO means you're meeting your personal Kyoto requirments.
If you're looking at using WVO then you really should refine it into biodiesel (not as good for your car as SVO but better than just WVO) because it contains water and acid. That requires playing around with things like concentrated sulphuric acid, but you can make cheap soap from the process aparently.
It's not as good for the enviroment as you're using electricity to mix the chemicals (normally) and some rather unpleasant chemicals, but if you've got a free or really cheap source of WVO it can be worth it (used to be worth it for duty reasons compared with SVO)

MikeT · Post by **MikeT** » 06 Jul 2007, 19:18

I'm astounded there is no drain hole but I'll be more astounded if ALL other xantias have, though there should be!

Maybe I won't try WVO.

Post by **CitroJim** » 06 Jul 2007, 19:57

MikeT wrote:I'm astounded there is no drain hole but I'll be more astounded if ALL other xantias have, though there should be!

That has always niggled me, water laying in the filler. Both mine do it and have no visible means of drainage.

There are a few areas of design on the Xantia that strike me as really fundamentally flawed, That is one and another is how if it has been raining when you open the tailgate, water drips in the boot

Likewise, opening the bonnet in wet weather cascades water down onto the engine, especially the alternator.

And don't get me started about the muppetry of the windscreen scuttle panel and the position of the air intake....

lolingram · Post by **lolingram** » 06 Jul 2007, 20:00

35MPG sounds about right for urban driving... Can't begin to imagine HOW a petrol Dagenhamobile will get anywhere close under the same circs...

So you can imagine my anticipation of better consumption when I took posession of a Citroen 1.9 diesel last month!

Initially, the figures look disappointing but I haven't done a concise calculation yet. For instance, the last refill of 19.54 litres ( I usually top up when the fuel light comes on continuously for more than 5 miles) has returned only 150 miles and the previous refills averaged about the same - £5 giving 42 miles, £10=84 etc.

MikeT · Post by **MikeT** » 06 Jul 2007, 23:31

lolingram wrote:35MPG sounds about right for urban driving... Can't begin to imagine HOW a petrol Dagenhamobile will get anywhere close under the same circs

I think I read the Citroen official consumption for this car was 8.4ltrs per 100kms.

Nobody else believes the mpg of the Granny either. But I'm not complaining.

Mind you, urban driving here is generally more relaxed than where I used to live.

Post by **philhoward** » 07 Jul 2007, 09:30

I used to get almost 40mpg from a Cavalier 2.0CDi - and I didn't hang about in that. I guess sometimes you get a "good 'un"...

I've now had 3 TD Xantias, all about the same vintage (94/95), and mpg has varied between 40 and 48mpg - on the same routes. 40mpg is pretty amazing from a Granada, though..but I did know someone who used to get high 30's from one, so it may be possible.

MikeT · Post by **MikeT** » 07 Jul 2007, 10:04

citrojim wrote: That has always niggled me, water laying in the filler. Both mine do it and have no visible means of drainage.

There are a few areas of design on the Xantia that strike me as really fundamentally flawed, That is one and another is how if it has been raining when you open the tailgate, water drips in the boot Likewise, opening the bonnet in wet weather cascades water down onto the engine, especially the alternator.

And don't get me started about the muppetry of the windscreen scuttle panel and the position of the air intake....

Maybe it doesn't rain in france

MikeT · Post by **MikeT** » 07 Jul 2007, 10:10

philhoward wrote:I guess sometimes you get a "good 'un"...

I've now had 3 TD Xantias, all about the same vintage (94/95), and mpg has varied between 40 and 48mpg - on the same routes.

These DOHC EFi engines have a good rep for mpg. Like I say, I'm not complaining

40-48mpg from a TD is what I was expecting but mine doesn't get anywhere near that and I'm wondering if it's a tuning issue. I haven't had to top up the oil at all though I recently did an oil change though I do have to add a dribble of coolany weekly, and I mean a just a sip.

jeremy · Post by **jeremy** » 07 Jul 2007, 10:32

There's not much tuning you can do on a diesel as thre is no mixture as such.

Does it warm up properly. Most have an advance mechanism to give a fast idle when cold which might affect power (don't notice it on our ZX 1.9D) but if the thermostat isn't working it may stay on.

Does it seem to go properly or is it slow (I know Xantia TD's aren't rapid due to their great weight). Does it sound right (too quiet may mean the timing is retatrded - too noisy - advanced), does it smoke?, can the turbo be felt coming in?

MikeT · Post by **MikeT** » 07 Jul 2007, 11:28

Hi jeremy,

It seems to warm up ok though I should replace the 'stat. I generally don't ask for much power when cold so can't comment on that.

I always suspected mine was down on power though I've nothing to compare it to having never driven a turbo diesel xantia with a catalytic converter. I suspect it's giving the same power as a 16i non-utrob petrol engine but that's a wild guess. I'm sure my Grannie 2.0i would see it off from the lights.

From cold, the engine is neither loud nor noisy and gets quieter when warm. I've complained of no smoke before now, relating smoke to power, and recently increased the smoke compensator by two turns and now I can see a mild haze behind me when revving it hard.

Yes, the turbo assists but it's nothing significant I don't think.

Post by **philhoward** » 07 Jul 2007, 11:38

MikeT wrote: These DOHC EFi engines have a good rep for mpg. Like I say, I'm not complaining

I know someone who'd disagree - he recently bought a 2.0 DOHC Sierra 4x4 for replace his 2.8 V6 version for economy reasons - it's only 2mpg better (24mpg vs 22pmg)...

MikeT wrote: 40-48mpg from a TD is what I was expecting but mine doesn't get anywhere near that and I'm wondering if it's a tuning issue. I haven't had to top up the oil at all though I recently did an oil change though I do have to add a dribble of coolany weekly, and I mean a just a sip.

When you're in the realms of high economy, every little thing makes a difference - type of tyres and the pressure, the condition of the air filter (needs to be spotless), brakes binding, injectors clean, exhaust sooted up...the list goes on...

Xaccers · Post by **Xaccers** » 07 Jul 2007, 14:59

Drain hole:

Right under the flap hinge

It is basically just a hole through to the wheel arch.

lolingram · Post by **lolingram** » 07 Jul 2007, 18:03

The good old XUD has been around for a long time now... not too fair to compare fuel economy agin CR contestants IMHO - especially in a heavyish Xantia bodyshell. The Hdi is chalk from cheese economy and driveability wise - over 7+ mpg or more. Above all, the Hdi will return v. good mpg under adverse urban driving whereas the XUDTD's consumptiuon will go under 30mpg in heavy traffic.

Of course the bullet-proof reliabity of the XUD is yet to be proven for the Hdi - likely to be perhaps even superior from the mechanical viewpoint, but the electronics........?

My wife runs a very pretty low mileage (79K) XUTD estate... my Hdi 90 Estate has well over 200k on it, a bit dented and street wise, but runs like a dream - everything works, and betters 46mpg on a trip up to the Somme from SE France including aircon cruising at 90mph!

I've now had 3 TD Xantias, all about the same vintage (94/95), and mpg has varied between 40 and 48mpg - on the same routes. 40mpg is pretty amazing from a Granada, though..but I did know someone who used to get high 30's from one, so it may be possible.

MikeT · Post by **MikeT** » 07 Jul 2007, 20:37

philhoward wrote:
MikeT wrote: These DOHC EFi engines have a good rep for mpg. Like I say, I'm not complaining
I know someone who'd disagree - he recently bought a 2.0 DOHC Sierra 4x4 for replace his 2.8 V6 version for economy reasons - it's only 2mpg better (24mpg vs 22pmg)
When you're in the realms of high economy, every little thing makes a difference - type of tyres and the pressure, the condition of the air filter (needs to be spotless), brakes binding, injectors clean, exhaust sooted up...the list goes on...

The Ford 2.0 DOHC 8V EFi, I should have said. 16V's guzzle.

I understand how many variables can affect mpg - new filters & oil recently fitted, brakes not binding, rarely use A/C or night driving, tyres checked regularly, can't say about clean injectors as at 119K miles they may be well very worn. Can they be DIY checked/tested?