I'm not 100% sure it will come yet, but been tentatively offered an 07 plate 1.9 TDI estate elegance. It will have between 70 and 80k on it and is in good condition.

Price will be circa 3.5k

I was after an SDI, but this seems a good price (its a part ex from somone who has ordered a new car)...and the fuel consumption compared to the SDI isnt THAT much different.

My questions are these......can I get the TDI remapped to improve the power curve to allow me to beat the SDI on fuel economy or can I fit a 6 speed gearbox to it? Are either feasible/practical/cost effective?

Happy to stimulate some discussion on this one.................

You can get the car remapped and that will improve your mpg provided you don't take advantage of the increased performance available. You could probably fit a vRS six speed gearbox but you'll also need to uprate the front springs for the increased weight and surely changing gearbox is a lot of expense and effort to try to save a couple of quid on fuel?! If maximum mpg is your aim I would suggest a comprehensive service (including air and fuel filters) to make sure the car is running as it should be. If the car has 15" or 16" wheels fitted change them to 14"s with 'eco' tyres in the standard 185/60/14 size

http://www.briskoda....__fromsearch__1

How many miles do you actually do each year? Look at the answers in that thread, SDI to TDI is circa £200 per 10k, same from TDI to (my) mpi though I didn't get much else from other petrol owners. If you're considering gearbox swaps i'm guessing you do enough mileage to warrant the cost of the box and the work so that's got to be 30+k a year? Get insurance quotes, factor in a turbo failure and a DMF failure (give yourself a worst case scenario but the clutch seems to survive a lot longer on a SDI as well) and see how comfortable you are with the numbers. Remember if you map your car you need to factor in the map cost, potential increased failure rate on things like the turbo and clutch and increase in insurance premiums, eco maps are still maps, also allow for the timing belt change every 60k or 4 years etc.

If I was doing 30k a year i'd prefer an SDI as fewer things to go wrong (SMF, no turbo and much simpler to work on). The price you've given is low for what's been offered, ask yourself why, even at p/x valuations on an 07 either the guy's gone in and waived a white flag at p/x time or it's cheap, what's the s/h like, does it need a service and a cam belt and some minor work to get through an MOT by any chance?

My questions are these......can I get the TDI remapped to improve the power curve to allow me to beat the SDI on fuel economy or can I fit a 6 speed gearbox to it? Are either feasible/practical/cost effective?

Happy to stimulate some discussion on this one.................

I have put 150k on mine so far and here are a few things i have found out....

had a look at changing to the 6 speed box but rulled it out in the end. its not a simple swap and there was something different that was missing on the PD100 engine that made it a non starter. I cant remember the details but if you have a search through my threads you should find it as I asked about it a while ago and got a lot of good info from some experienced members.

on a remap for economy then yes you can improve a bit. I also went from 15" to 16" wheels to accomodate 312mm brakes with my map so ended up with no change but I fitted the wheels first and went from about 49mpg down to 40-42mpg. when mapped I was back up to 48-50mpg so without changing the wheels I would guestimate that 5+ mpg is reasonable (again, as long as you dont use the extra power) - the map gives a far more drivable power curve and is a HUGE improvement on standard.

the DMF and clutch worries are largely dependent on your driving style. mine is at 150k and has been mapped for 40K of that. still on the origonal clutch and DMF and when checked a few weeks ago the clutch still had plenty of life in it.

if you plan on doing standing 1/4 miles every time you get in the car then thats a different matter but driven normally and with a little mechanical sympathy they are fine (that said I can make the clutch slip if I boot it from a stand still but thats just due to the increaced power being slightly more than it can handle - it wont slip during normal use)

cost wise the map for me was a no brainer - I do about 25K a year and if you factor in a 5mpg improvement (which I think is conservative) then the payback is only one year ymmv

You can get the PD100 remapped to around 135 upwards which is quite safe. Again the tyres and size of all will make the biggest difference and is your cheapest alternative.

Even a standard pd100 you should be seeing mid 50's- 60's on the motorway when driven between 65-70!

And you have much more power than an SDI

Thanks, some food for thought there.

A friend of mine works for a skoda dealership hence the sensible price. I don't have details on the service history of the vehicle yet so not sure if its had a belt change yet and how much MOT etc it has. I am aware it has a dent in the rear quarter.....no paint damage, just a dent (not seen it yet) so should PDR out but even if not its not the end of the world as I'll kill the car over time anyway!! The point is though its not forecourt quality which is why it will come at the right price.

My mileage is about 18-20k a year.

I love the missus' fuel consumption in the SDI but I do like the idea of having a bit of grunt at my disposal as i do a lot of long distance travelling over A roads and the ability to ovettake swiftly and cleanly is always useful.

With the extra info it seems more realistic TBH skip the gearbox idea, all things being equal it's only going to cost you an extra £360-400 a year in fuel vs an SDI in fuel, OK the insurance is probably a little higher but it'll be better to drive. If you do map it then short term it will cost you more (cost of map+ additional insurance premium) but long term you could save. Either way it's £360-400 cheaper than doing the same mileage in something that's petrol, just remember to check when the timing belt was done last.

Thanks avalon. Do all you guys tell the insurance about maps? What kind of changes in premium are we talking about?

The whole idea of changing my car is to kill as many motoring costs as I can so adding a map and then extra insurance costs (I'm in quite a high cost area anyway) is kinda shooting myself in the foot a bit. The whole idea of the exercise was to try and get the economy of a TDI up to SDI territory as on paper theres only about 2mpg difference.

Personally i'd always tell my insurance company. Some aren't that bothered and make no charge, others operate a % of power increase banding and others say 'No' and some will want silly money, I tend to get better results with brokers or specialists than comparison sites.

The reason I always tell them is this: My ex used to work for a well known insurance intermediary, one of the things I learned as a result was you tell your insurance company everything and let them decide what they are bothered about. In one case she dealt with the insurance company was going to pay out on a 3rd party claim as it's insured was judged to be at fault. The problem was the assessor identified the insured car had a number of (undeclared) modifications, this lead to further detailed investigation at which point they decided he'd significantly misrepresented the car/risk to them. The options were charge the difference between the premium that had been paid and the true premium and settle the claim paying out for both, this is normally done where for example the insured party acted in good faith and wasn't aware the set of alloys on a 2nd hand car weren't standard etc. or pay the 3rd party claim but refuse the claim of the insured driver and then go about recovering the cost of the 3rd party claim from the insured and the companies reasonable costs in doing so (read expensive). I don't know what happened but I doubt it was the former.