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..