Former

I've no idea about welding, ask the person who's quoting the job. Nothing wrong with a patch if it's done well but if later more patches are needed it can get more awkward and perhaps proportionally more expensive.

I and I expect others would be (very) surprised if the inner sill(s) weren't affected to some extent or other. I have absolutely no need to be fair to most in the motor trade, but most customers do just want the bare minimum done and don't appreciate warnings (bad news) and will take their business elsewhere on being told but a proper good person or place will tell you just because they are good but also if they're good they often don't need to worry about losing that sort of customer as they'll have enough customers and work already. That's the problem, you can't get to many decent folk in the car trade as they have a waiting list. As I put before it's no good telling you to put underseal on an old car as they could possibly speed the rusting. The sills would have needed cavity rust proofing as the rust would have (mostly?) been from the inside not outside. Doesn't the VW indy know of good welders or bodyshops?

If it's just the sills then replacing the sills will deal with the rust on the sills but you do need to find out exactly what sills are to be replaced, are they two part, three part, doing one side of the car or both sides. Putting something on the underside of the car can be a good idea but not anything that seals in rust that has already started from the other side of the seal. You also want to know why the sill rusted so badly seemingly so quickly, though it could have been there a long time building, are drain points blocked or a leak/rainwater goes to that area. Remember they're only quoting you for the job you have asked about they're not looking for rust elsewhere, that's future work. If they're decent if you ask they can give a quick look over the car and give their personal opinion if they've worked on enough of your model, or known about them or just generally with repairing old cars.

Summer tyres from the manufacturers. - https://www.bridgestone.co.uk/our-products/car-tyres/summer-tyres-turanza https://www.continental-tyres.co.uk/b2c/car/search-results.html?pogSegment1MappingDTacs=passenger_car&season=Summer https://www.falkentyre.com/en/tyres/car-tyreshttps://www.barum-tyres.com/car/expert-advice/tyre-knowledge/difference-between-summer-allseason-and-winter-tyres Too many 'brands' to look at but here's one list. - https://www.tyrereviews.com/Tyre/

Getting rubber has been a problem for a while back and the tyres aren't just rubber, if you think back a few years and all the funky tyre model names and descriptions as new ingredients are tried out in formulations. I've been buying car tyres for over 40 years but the last 5-10 I've noticed bigger differences. With the weight of modern cars (overweight for most German marques) and the fashion for overwide wheels and tyres things are perhaps more noticeable, though they certainly are with a relatively very lightweight old car like mine on 145/80R13 or 155/80R13 tyres designed for city cars.

Tom that's a lot of visible rot the old iceberg theory often holds. You need either a mate who's good at welding or get a quote or opinion from a good professional welder/bodyshop. I was with a mate today when he was sorting getting a rusty sill sorted on his Jag, £30 for the part but that's just the start of the work and often more is discovered after the work is started. If the welding job is done properly you don't need worry about strength and if it's done properly it should last a reasonable time it's just that if there's rust there where else will rust be discovered and how often. Anything can be sorted, if you have enough money and perhaps time, as I said before sometimes you need to decide when to cut your losses and not throw (more) good money after bad.

No it's not and would be a bad practice in some vehicles older than you but as you want to learn about this you can find the info and decide for yourself rather than me direct you to explanations I like. I think you're missing out gearing, for uphills if you can carry as much momentum into them, say from a downhill, that will help. Most modern cars and hindered by their weight (over for German cars perhaps) and the fashion for overwide wheels and tyres doesn't help, improving on what is already loaded against the car is not to add to it and if possible reduce it. Loads of info about for you to decide which of it you like the look of. The part with the car being out of gear (and foot off clutch) I don't agree with as a good driving technique or that it will save petrol but again you can research and make up your own mind.

As per softscoop's link, but sometimes the manufacture date code is on the inside wall of the tyre. You should also find on the tyre wall where the tyre is made, many are made in China and some of those can be good and some really not so good for general use. Personally I'd use the Runway as (only an emergency) spare and fit four new tyres otherwise you could have three different makes, models types and age of tyres on the car being used which might be fine but having a full set of new tyres will give more confidence and possible/probably (depending on what you buy) better performance. Is your wife's Corsa a sporty type model or modified/souped-up to have those Yanky tires?

MPGwatcher, as a young person of 29 and inexperienced driver you might be believing what the car's computer tells you as regards fuel consumption which may vary from the reality, what you see on a computer screen isn't always correct and with a car it not only depends on the programming but also the accuracy the measuring at various points and the parameters and rounding up and down of the programing. Try, fill your tank until the first click of the petrol pump, zero your trip meter then when you next refill note how many litres it takes to fill to the first click on the pump, note the mileage, divide the litres into the mileage for litres per mile - or first divide the litres by 4.54 to get number of gallons into the mileage to give mile per gallon. Then see how this compares with what the computer tells you, hopefully it won't be too far different. Not a good idea, surely they don't teach that now? What is forgotten about start/stop is that it's also about reducing emissions, lot less emissions when the engine is not running.

I must admit even though I'm a bit fan of Driver's Handbooks the Fabia one is very poor in some places, I think the 7 litre reserve is some sort of can (canister) that I've never seen as my wife's car was second-hand/used/"pre-loved" or not provided in this country(?) - see below. When my wife's Fabia mk3 was a lot lower on petrol than usual with the amber fuel (pump) warning lit and countdown of range the fill of petrol suggested about 45 litres to the tank. Not a good idea in a modern car especially during (very) hot weather like we have now (well at least where I am). I can do that in my 1973 car but a modern car is a different matter. I think a mistake many modern drivers make is to take the car's computer's consumption figures or where the needle is on the car's fuel gauge rather than working out simply fuel used by petrol pump display divided into mileage from trip or odometer.

I'll have to take your word for it being much changed from previously, I can't remember ever using one you have to pay for or the last time I used those that were free to use only that it must have been very many years ago.

Just code it as JCB, the computer won't know any different or care as long as you have the type of battery correct, alter the battery capacity (ah) as required and alter the serial number (change the last 1 to 2) the computer will be satisfied.

Sorry George I thought you meant accuracy of pressure gauge. For inflating those wheezy electric inflators that come with the cars will inflate the tyres then check with accurate gauge and deflate to required pressure. You must admit that you're in the category of the few rather than the many - in many ways. 😉

You've lost me with that - but I've not used a petrol station tyre pressure gauge for I don't know how long, probably decades, I'm too tight and grouchy old man to queue to test a petrol station gauge. Let's try another angle then. Better to have consistency with your readings, taken when the tyres are 'cold' rather than warmed from driving (unless the petrol station is close) and using the same gauge each time rather than different gauges. Increasing the tyre pressures on my wife's Fabia Mk3 makes a noticeable difference to the rolling resistance on the tyres, also to the handling, never checked the mpg figures for this but would expect it to help with MPG. Again the big difference is going to be from the driver and/or the way they drive, and this can be transferred to similar vehicles. Vehicle selection would help and perhaps not following the crowd with vehicle fashions, though some of that is hard to avoid. Of course greater concern about mpg is often in fashion when there are fuel crisis and follows the circle of fashion as those old enough have seen a few times (even if they can't remember the details).

MPGwatcher economic driving is knowing more about driving than deeper mechanical. Start with the basics like tyres, the unneeded weight the car carries all the stuff and advice you'll find on AA/RAC type sites and the specialist hypermiling sites. Training yourself to drive more economically and preparing the vehicle for economic driving will also be the most cost effective methods. I'd recommend that you don't trust petrol station tyre pressure gauges and buy a good quality one of your own, doesn't have to be expensive, also don't rely on the car's (especially with a VW) mpg figure but work it out yourself by how many litre it takes to fill the car's tank from the last fill and divide by the trip mileage. The speedo/trip may be very slightly out but the error will be reasonably consistent and petrol pumps should be near enough - unless you are trained to do this professionally with professional equipment you have to accept things aren't laboratory precise. There's no magic pills, mainly just the basics that have been about for years.

...but what about town/city stop, start driving. 😁

The stupid thing was not adopting the metric system fully in the 1960s. Mid to late 60s as a young lad I was taught at school about metres and decimetres and then centimetres, the following year at a different school I taught about archaic measurements like a chain! 🤣

Might be a typo but as I have to remind my wife as she always mixes it up it's (and it's one figure I can actually remember) - 4.546 - next digit after decimal place is 0 (nought) so stick to three decimal places, if not two decimal places. ETA: I'm also not sure you have the tank capacity right by the few times I've refuelled my wife's 2015 Fabia but I'd never be allowed to run the tank dry to find out it's capacity in relation to the fuel gauge.

Out of interest what make, model and age (manufactured date) are those cracked tyres?

Personally, ASAP or straight away, I'd fit four new tyres of the same make, type, model and age (take it steady on the new set of tyres for the first 100 miles, 200 if wet, and check the wheel nuts for torque after the first 30 miles or so). If the current fourth tyre is OK you could keep it in the boot as an emergency spare if it's not the same make, type, model and age as the other 3 or you'd need to keep checking its still OK. Tyres go like that from any combination or permutation of - lack of use, age, being kept outside, being cheaply made.

And just thought of this - you could also try angling the sun visor so that the air deflected towards you rather over your head and other sun visor to deflect the air back down. I've not tried this with the air-con but I angle the sun visors to deflect the air to the windscreen when clearing the windscreen with heat and/or air-con.

With my old car I have 4/60 air-con, open 4 windows and go at 60. Try starting with it at screen, and not recirculating, and see if that's better before switching to face. I loathe to get into a hot cabin, with the Fabia I have to open the door(s) then put the key in to turn the ignition on to drop the (front) windows with the door(s) open to let some hot air out before I get in the car. Normally I don't like having the air-con on but for a hot interior it's a must, if possible.

Sorry if it's a Mk3 I forgot about all the manufacturers and dealership delays. On my wife's 2015 I always find it more effective to set it to windscreen to feel the cold air sooner from start, I turn off the recirculating and got to fan speed 2, the car's owner doesn't like the noise on speeds 3 and 4 anyway even if I instruction that the passenger shouldn't interfere with the driver's controls.

That was my only idea, other than perhaps drawing attention to your thread to those that might know. Now we wait.

Have you tried another scan tool?