Petrol Vs Diesel- Update 22/09/11
 

As you can no doubt see from my garage/sig, I like RWD petrol cars..:D

They provide an involving driving experience, and can return decent figures if driven sympathetically..:turtle:

However, I spend plenty of time driving the m8 motorway (Highway). this cannot be classed as fun, ever.

2 lanes each way, tailbacks (even at 8pm on a sunday!) and literally NO redeeming features/bends to enjoy RWD



These trips are either a 50 mile round trip commute or a 130 mile roud trip to my Unit. Either way, they are boring and tedious in extreme.

Thankfully, the Unit run has some twisties that I can enjoy (at legal speeds) so I can have some RWD fun for 16 miles or so.



Being in my colleague's new car (see here: http://ecomodder.com/forum/showthrea...are-18683.html )

I saw that with no hypermiling techniques, she was already doing approx 15-20 UK MPG better than my best petrol car..



So I'm thinking- can I get a Diesel car that is frugal on the hateful M8, yet fun on the twisties?

I'm not fussed whether RWD/FWD, but it needs to be manual and have a decent chassis setup.

and a budget of £1000

Payback period needs to be less than 2 years (based on 18000 miles PA)

e.g., on fuel my 318iS would use 445.55 UK Gal at a cost of £6.05 a gallon, giving a total of £2695.57

so at 55mpg, the diesel would use 327.28 UK Gal at a cost of £6.18 a gallon, giving a total of £2022.59

saving £672.98.. (based on NO hypermiling, so likely to be more)


Or do I just spend a few hundred fitting LPG to the iS, and enjoying filling at £0.70/litre, and concentrate on aero/engine and hypermiling techniques?

What would you do, and why?

If your iS is in good condition (will not need costly repairs in the near future) then I`m for LPG all the way. Because you get to keep all the fun while driving a lot cheaper, not to mention that LPG is friendlier to the enviroment and also to the engine, you can prolong oil changes with it.

Getting another used car is always a lottery and diesels under £1000 are prone to rattle, leak, smoke, understeer and be a pain in the arse way more than a 318iS can ever be.

As from personal experience, years ago I went from an E34 to a 1.8Td Mondeo and although the Mondeo was 6 years younger, driving it was always a sob story compared to the joys of the BMW, not to even start mentioning the build quality difference and repair nightmares.

Given the premium for diesel in the UK, I suggest you look for something fairly light and extra-frugal like the VW / Seat / Skoda TDi - maybe even audi if you can get a decent one in that price range.
You're not going to like the SDi versions - frugal but agonizingly slow. ;)

If you pick the right TDi, you can run on biodiesel.

Are the conversions that cheap in the UK ?

Here you'd be looking at 1500-2500 euro.

get a 1982 to 1985 Mercedes 300D with a five speed manual. Then import an American engine with the turbo. The turbo models got better mileage and had more power . Its weird they never sold them in Europe.

That’s very fair comment you make..I simply cant afford a new enough Ford/mazda/toyota to get the same feeling of quality.

Certainly the element of “ better the devil you know” makes keeping the iS a prudent option..wonder how much a 320d lump is?

I’d thought of that, but the PD/various engine codes can be a nightmare to work out..

the Sdi on the other hand in say, a Skoda Felicia Estate on coilovers.. could be a hoot!

I’ve fired off some emails for a quote..

If I assume 35mpg on LPG (I know it drops mpg circa 10%), and a cost of £0.70 a litre, then 18000 miles costs £1636.56…So even at £1000 it pays back in a year

That’s an awesome suggestion! :DExcept for 3 things:

1. I already have a very old daily driver (my 1988 320i) so get my fix of hammer based maintenance:rolleyes:

2. The W123/124 tend to be pretty rotten over here now, especially in my sub £1000 price bracket

3. The burd wouldn’t drive it! The iS is currently her daily, so whatever replaces it must be liked by her.

I'd propose a Peugeot 106/Citroen Saxo with 1.5D - it's light, it gets good milage, you can easily find it for ~1000€, and it has great potential for aeromodding.

Yeah been looking at those..not a lot around you though as they're so small and light..

but the 1.5d is about as good as the 1.9 sdi engine, so not thirsty at all

Have you ever tried driving a Saxo or a 106 on the motorway and then switching back to the e36?
Try it and compare the stability, break ability, noise levels, allround comfort and not to mention the survivability in case an accident happens ;>

Yeah, I've driven plenty saxos etc as I used to work at a car auction...

They're not grand, but probably actually no worse in terms of occupant safety than my e30..

Yeah, but AFAIK, it's in the manual wether you can run BioDiesel (RME) or not.

Same for the SDi anyway.
But that's not going to be a hoot if you're looking at anything vaguely resembling performance.


Fine when it's new, but on a 13 year old car :confused:

I'll keep an eye out for one with a manual then..:thumbup:

Look at it like this, Repayments on a new car like this are approx £350 a month, with a hefty deposit plus the additional £1000 for LPG..

Or I have a £500 car with £1000 LPG fitted- that's just over 4 month's REPAYMENTS on a new car..

Plus I cna sort this one without a computing science degree:rolleyes:

Before you dig into the SDi frugality, don't forget they have a fragile gearbox - shared only with the 1.6 Petrol (and we know how popular they are) and not the same as the TDi. Plus the gearing is lower so as well as being very very very very slow they are also noisier and thirstier than they need to be.

A quick Autotrader search with 10 miles and £1k max price brings up quite a few. How about a Vectra DTi (the good one with an intercooller) or how about the minicabbers old fave the 406 - there's a 1999 facelift estate HDi with 110K miles on it near me.

If you want a bit of go and some reasonable modern-ness how about a late-ish 1.4 HDi 206 ? Or even a 2.0 ?

2001 PEUGEOT 206 DIESEL 3 DOOR

http://pictures2.autotrader.co.uk/im...266&height=200

£675, although the ad doesn't give mileage so I suspect its been to Mars and back.

EDIT - I would also skip LPG, adds weight and you need to do about 18K miles to get your money back. Plus your iS will be worth more kept in original condition.

Were there any good DTi's then ?

I've had a couple of Astra company cars.
The 1.7 DTi was a snail.
Didn't burn much, but didn't go either.

The 2.0 DTi was a two-stroke diesel.
Over the regular oil change interval, I added almost as much oil as was in it.
That was considered OK, as others burned even more oil.
In the beginning, we got 1L oil bottles to fill up. Later on, 5L bottles.

Dunno if GM ever got that oil issue sorted.

You are probably right ;) Mrs A had a company hack Di-16V in 2000 the engine of which was impressively reliable, smooth and economical given it had been abused by pretty much everyone else in the company prior to her using it. The rest of the car was the usual GM mix of poor design and awful quality, combined with strange smells. Wretched, but cheap to run. Never checked the oil though. :cool:

It was preferred to the 4dr 325i BMW she had before though - this was the ex-finance director's pride and joy. Which was odd as it lacked a lot of "go" and drank like a wino locked into threshers after closing time. Someone resembling me may have practised drifting it round Sherifhall roundabout at 2am going to the 24 hour pharmacy when A-junior was running a temperature which probably didn't do the economy or tyres much good.

One other thought would be an old-body but facelifted Meganne with the later DCi engine instead of the old dT.

http://www.motorsdb.com/renault/rena...MG-bli-061.jpg

Double bonus if you get one of the ultra rare 4 door "Classic" models.

Or what about a Polo "D" like the one Mr Chalmers (late of this parish) has (or had) ?

I’m gonna avoid the French Peugeot/Renault lot you’ve suggested, as I know too many folks that have had issues with HDi lumps.. and the 206 is a Hateful Hateful car!:mad:

If I go Diseasal, it’ll be German or Japanese..but as you say, probably avoiding the Sdi setup from VW

Depends what the LPG quotes are like:thumbup:


Herein lies the reason that the only Vauxhall I’d look at would be an Omega 2.5td..and even then it’s not that good a lump(and I know it’s a BMW lump)..but its RWD:rolleyes:

We'll have to agree to disagree on the 206, its fine for a shopping trolley and has decent handling (on good tyres mind). Its as heavy as a Mk3 Cavalier though.

HDis can be fragile but if it has enough miles it will carry on. The DCi is a decent lump - avoid the 1.9 though, the 1.5 does mega MPG.

Omegas rust, and the BMW lump has that issue with the fuel pump as in each pump is keyed to the engine so if it goes pop you have to go main dealer rather than just get a replacement. If you want a BMW Diesel then there is the options of the 325tds or 525 version, or the later 320d - just remember to remove the intake manifold vanes.

Jap Diesels are always a generation behind.

The 206 is like a badly built ford Fiesta..

French diesels were at their best about the 405- the 1.9td was a rugged thing, and a swap to non turbo injectors helps lots..

similar with the Cavaliers with the izuzu lump-manual FPR ftw!

As for the Omega, its a well known fact that the m51 is a horrific engine, with far too much electronic gubbery for its own good.

I've a friend with a 320d (150bhp), £1500 for a new turbo every 100k miles is not my thing..

I wouldn't dismiss the French option out of hand - Renault, PSA and Audi/VW/Merc/BMW have had good and off days with oil burners. If you are willing to consider it a 205 DTurbo is a fun little rocket, not the 1.9 from the 405/306 but a non-intercoolled 1.8 but still pretty quick. There were some run-out "Mardis-Gras" models with DTurbo engines which are little sleepers but they were made in Morocco which last time I checked is not well known for car production.

However if you are going to stick with German then how about an off the wall suggestion - a 190D - 2.5. Basically take the engine out of a E-class 250D and mate it to the chassis of a 190E-2.6 (with the modified bulkhead). Auto and manual options. And none of the rust problems of the C-class. Oh and very veggie-friendly.

Or even if you are willing to go Brit then I would have a local search for a late Rover/MG model with the Diesel 2.0 turbo. I had a test drive in a ZS with the 115hp lump and it flew, and the old Rover 200/25/ZS chassis was good enough for me to pass and outrun a Focus 2.0 Ghia on the A701 in my 220SDi in 1997. The Rover 200 models rusted a lot but I think the 25/MG ones are slightly better.

http://www.sniffpetrol.com/AdRover25.jpg

Or for ultimate cool and mega MPG an AX 1.5D - veggie friendly and you know you can get 80 MPG out of one.

TBH, if going Diseasal, I'd be looking for a later car than I currently have- If its a "Daily" I want it to be easy to get parts for, and possibly "more" reliable than the cars I run at the moment:thumbup:

However, deffo not up for a Rover, they make the 206 look acceptible.

It'd probably have to be something like a 306 TD /passat tdi/golf tdi or Skoda octavia:thumbup:

I feel we have not bonded :) Any Rover not a classic will be later than anything to the left of your posting :D

It was a left field suggestion, they are good fun (handle better than their image) and the L-Series is less "grenadable" than the XUDT - HGF :p

And as for a Golf, I assume a Mk IV. Are you considering a change of career towards hair care ? ;)

The only rovers worth having are pre the SD1:thumbup:

Mk3 golfs were built up to 97, so not really. plus mk IV are too "electrickery" for my liking:eek:

hows your 2nd Salon going?

Mk3 Golf, are you stark raving bonkers :eek: :rolleyes: ;)

They're hammerfixable and I can weld..

Wherein lies theissues?

ye of ROver and french faith!:eek::D

At least Rover didn't have to have a night shift on to fix what the day shift had made - thats what VW had to do with the Mk3.

Why I chose my Rover over a Pug 306 (which was the #1 hatch at the time - 1997) what the interior if I'm honest. The Pug was slightly bigger but the Rover was just so much a nicer place to be - the seats came from the 800, the instruments from the 600 as did most of the switches, the dash was solid and the interior didn't smell really bad like the Pug one did. Even the Focus was poor compared to it, the plastic was hard compared to the Rover's soft touch and it rattled a lot.

I dodged the bullet of the K-series HGF by choosing the Diesel, and as someone else was paying I didn't mind that it was overpriced for what it was - and it was.

Plus it was white - so in the outside lane of any motorway all people saw was a white Rover with its headlights on... :D

EDIT - If you do go Mk3 - remember that the Mk3 is so strange that the 5 door shell is actually STIFFER than the 3 door one, and is therefore preferred. ;)

Yeah they didnt bother fixing the faults:D SD1 with the extractor fans DRAWING IN moisture to the painting line?Genius!

I like how the best parts of the car are from OTHER models from the range, and even then, not great cars.. I get what you mean though the 200/400 were decent back in the day-they really went downhill in the 25/45 stage.

If its a diesel golf i'll not be othered about torsional rigidity!:turtle:

Apparently it was called Project Drive where they tried to remove items that nobody would notice... :rolleyes:

Is there any insight 1 in Scotland ? At what price ?

I can barely imagine any 1000L diesel being more ecological than your gasoline car. Today no diesel is as clean as a 2000 prius or a 2000 insight... It all depends on your ecological sensibility and the ecological problem you want to solve :

• lower CO2 emissions/dinosaur juice consumption for cooler atmosphere in 50 years
• lower pollutants (particles/NOX) emissions for better air nowadays

CO2 can be lowered by hypermiling/ecomodding
You can emit a lot more pollutants by racing your car, but hypermiling/ecomodding will not have as much impact than for consumption.

Now if this is about saving money only then a spreadsheet is your best friend, depending also on your mechanical skills.

Denis, saving money one tank at a time to buy a Prius that will generate much less pollutants but cost a little more per distance.

Which way you choose depends, as you tap, on your view. In this case I think the focus is on reducing fuel usage and cost rather than on reducing CO2 - but the OP can answer that one directly.

CO2 being a problem or not is a whole different debate, and it may go into politics (I have reputation for this so I will go no further...) :rolleyes:

As for the Mk1 Insight I have seen 2 in the UK (they were both the same colour and in Scotland so it may have been the same one twice...) they are rare - very. There is apparently an expert on them and especially the batteries used who is based in the UK but I haven't researched it more than knowing this.

I did do a search when I was looking for a car recently and found a couple on Autotrader and one on e-bay and they are spendy for what is really a tiny Honda.

On reflection though 320, that would make an interesting project if you could fine one ? Not for under 1K though I would wager.

After some wait for conversion costs for the iS to come back, it seems that a multipoint LPG system can be had for about £895 INC Vat, but about 400 miles away (approx £120 Fuel cost)

or a single point one installed for £950 +vat (£1140) about 5 miles along the road..



So I took these figures and did som "back of a beermat" maths based on the current cost for My iS, and the costs of:

a Diesel getting 55mpg (UK) (£1.379/litre)

an LPG car getting 30mpg (UK) (£0.70/litre)

Miles to date Extrapolated to a year
Total Miles 11,767.1 15,297.2
Total Cost £1,778.05 £2,311.47
£ per mile Fuel £0.15

55mpg Diesel Fuel £1,341.22 -£436.83 £1,743.59 -£567.88
£ per mile Fuel £0.11

33mpg LPG £1,248.18 -£529.87 £1,622.63 -£688.84
£ per mile Fuel £0.11


These seem to suggest I'd pay back an LPG conversion in approx 2years.. But- Do I wanna have such Low MPG?

or is Diseasal a plan?

THere's an iS near to me for wale with LPG fitted-I could buy it, strip it and sell it on..

too many choices!

What would you do?

Would you be keeping the 318is?

Since the approx. fuel costs are the same per mile traveled, I would say that if you can trade in your car and pay 1000 out of pocket, then go diesel. Then you would have the option to go grease in the future, which would mean possibly free fuel.

Otherwise fit the LPG to your car. You would have to factor in diesel repairs, and whether they would cost more into your analysis, also.

2 years payback time on a 16 year old car ?

Unless I'd want to turn it into a nice classic / historical car I wouldn't put much money in a 16 yo car.
But then, if I wanted to turn it into a true classic, I wouldn't add LPG ;)

I'd expect it to be more expensive than a petrol Beemer to buy ?

LPG has one other benefit which may apply to your car - once converted you can re-register it as an alternative fuel vehicle which means you save on annual road tax - probably an amount which would pay for perhaps 2-3 tanks of petrol, or 3-6 tanks of LPG.

You also get to drive in London's congestion charge zone for free. But as you are 450 miles away thats maybe not such a benefit.

Not sure what you mean about the converted 318 near you, do you mean you would strip the LPG off and add it to yours ? Doesn't an installation have to be approved by someone, not sure on this though.

There are rumours (nothing stronger than that though) of a change in the taxation for LPG, and these changes usually result in uk.gov removing more of our money not the other way round.

Can't help thinking that if I ran a 328i, 330i or even an M3 then this would make sense, but I wouldn't convert a car with reasonable MPG like your 318is. As you like the iS and are torn about letting it go, could you SORN it instead and run a smoker diesel hatch as an everyday car - bangernomics style ? Or as an alternative get your 335 converted and run that instead.

Or for top spannering swap the 335 engine into the iS - but keep everything else looking standard. :cool:

I'm currently keeping the iS as it stands.- happy to invest in it if required.

With diesels I can see there being more potential for issues repairs wise-esp on say a 200 TDI.

Whats the Payback period on your Volvo;)?

The car has depreciated fully- and assuming it ran for antother two years it'd still be worth what I paid, and have covered the cost of LPG conversion...


I also have a ropey old single point LPG kit lying at the unit- I'm just loathe to fit it unless I can get someone to guide me..

It wouldnt be as efficient, but it cost £180 so payback would be almost instantaneous

PS - to my previous post, Car Mechanics is covering LPG in the current issue, including an old single point system fitting.

I'l look out for thaat!

all good newsagents i presume?