Diesel Vs. Petrol
Discussion
I live in Surrey and work in Cheshire (short term thing - new job), and I'm currently commuting on a weekly basis to the place I'm staying. Over the course of my week, I'm doing around 600 miles, and it's costing me a fortune in fuel (2.0TS Alfa GTV).
I've been looking to chop the Alfa in for a Diesel, but I don't really want to, as even though the Alfa is too small, pretty uncomfortable for my size (6'5"), and is everything I don't really like in a car (small 4 pot, FWD), I really like it for some reason.
Now, I'd not taken much notice before - literally 'assumed' that the cost of running a diesel was significantly less than that of a petrol car. I was sitting at a roundabout, opposite a petrol station last night, and I noticed the price differences of fuel - £1.31 per litre for Petrol and £1.39 per litre for Diesel. Now, that doesn't mean much in real terms (35mpg in a petrol car would need to be 37mpg in a diesel car to equal the cost), but is it the case that using 'man maths' this isn't really worth it anymore?
I've been looking to chop the Alfa in for a Diesel, but I don't really want to, as even though the Alfa is too small, pretty uncomfortable for my size (6'5"), and is everything I don't really like in a car (small 4 pot, FWD), I really like it for some reason.
Now, I'd not taken much notice before - literally 'assumed' that the cost of running a diesel was significantly less than that of a petrol car. I was sitting at a roundabout, opposite a petrol station last night, and I noticed the price differences of fuel - £1.31 per litre for Petrol and £1.39 per litre for Diesel. Now, that doesn't mean much in real terms (35mpg in a petrol car would need to be 37mpg in a diesel car to equal the cost), but is it the case that using 'man maths' this isn't really worth it anymore?
You need to factor in purchase price and depreciation for the maths to work.
Eg We have a 3.0tdi Audi A6 and a 3.0l petrol Subaru Outback, both the same age with the Audi now on 100k miles and the Outback on 60k miles
The second hand value of both was about the same in 2010, now the Audi is worth about £10-11k and the Outback £7-8k (looking at adverts on the internet).
So that's an extra £1k a year depreciation for the petrol car or 763 litres of petrol. Large petrol engines are not popular with buyers, an Outback with a diesel engine is worth £1-2k more than the petrol.
Outback averages 25mpg, Audi averages 36mpg.
Eg We have a 3.0tdi Audi A6 and a 3.0l petrol Subaru Outback, both the same age with the Audi now on 100k miles and the Outback on 60k miles
The second hand value of both was about the same in 2010, now the Audi is worth about £10-11k and the Outback £7-8k (looking at adverts on the internet).
So that's an extra £1k a year depreciation for the petrol car or 763 litres of petrol. Large petrol engines are not popular with buyers, an Outback with a diesel engine is worth £1-2k more than the petrol.
Outback averages 25mpg, Audi averages 36mpg.
I do similar mileage a week. I chopped in my lovely Subaru Legacy Tourer 2.5 for a BMW 320d tourer.
The change? £150 a week fuel for the Legacy is now £75 a week. It's not nice to do and god the Beemer sounds awful, especially as it's got colder , and yes I do miss the silky smoothness of the Boxer engine, the sunroof, the fact it's different, but the wallet is better for it and is now only being raped by my RX-8.
Regards
The change? £150 a week fuel for the Legacy is now £75 a week. It's not nice to do and god the Beemer sounds awful, especially as it's got colder , and yes I do miss the silky smoothness of the Boxer engine, the sunroof, the fact it's different, but the wallet is better for it and is now only being raped by my RX-8.
Regards
daemon said:
Must be at least a week since diesel v petrol was debated.
But this is about cost not about all of the other soft issues. Although I am certain the thread will end up in the usual diesel vs petrol debate that revoles around all diesels being noisy smelly slow tractors and all petrol cars quasi F1 supercars.20,000 miles a year was the old figure IIRC.
Our lass does 300miles a week in my SAAB 9-3 diesel and I've been weighing up letting her use the £900 petrol Mondeo and I genuinely can't fathom a TCO.
The SAAB is good for 50mpg for her, but on diesel. BUT the Saab is £600 PA on tyres, £200-£300PA on servicing, £1200PA on insurance and I worry about the pristine paintwork getting f
ked-up at her work (A uni/college).
The Mondeo is only good for 30-42mpg, on petrol - CHEAPER. I can service myself for £35pa, insurance is £300-£400PA for same cover as Saab, 4x tyres are £300, and the bodywork is "well used" so I couldn't give a fk anyways.
So the phrase "swings and roundabouts" springs to mind.
In the end the safety of the Saab complete with nanny-state protection and reliabillity are what mean she uses it
Our lass does 300miles a week in my SAAB 9-3 diesel and I've been weighing up letting her use the £900 petrol Mondeo and I genuinely can't fathom a TCO.
The SAAB is good for 50mpg for her, but on diesel. BUT the Saab is £600 PA on tyres, £200-£300PA on servicing, £1200PA on insurance and I worry about the pristine paintwork getting f
ked-up at her work (A uni/college).The Mondeo is only good for 30-42mpg, on petrol - CHEAPER. I can service myself for £35pa, insurance is £300-£400PA for same cover as Saab, 4x tyres are £300, and the bodywork is "well used" so I couldn't give a f
k anyways.So the phrase "swings and roundabouts" springs to mind.
In the end the safety of the Saab complete with nanny-state protection and reliabillity are what mean she uses it
Bear Phils said:
You also have to wonder about the issues with modern diesel cars. Injectors, flywheels, turbos etc. If they need replaced your saving may not be so great
Hmm another interesting point. Saab is on 95k at 2006 plate and DMF will need doing next year. Turbo is mildly noisy compared to new, but nothing major.From memory, via mates rates the DMF/Clutch is about a £750 job and the turbo about £400.
On the other hand, the snotter (2002 Mondeo 1800lx) has a rattly plenum (Common issue) and can be fixed for about £30. Timing chains mean it's good for years, and they left the factory without any subframe bushes it seems.
Bear Phils said:
You also have to wonder about the issues with modern diesel cars. Injectors, flywheels, turbos etc. If they need replaced your saving may not be so great
Mine is 100k in. All that has been replaced is brake discs and pads and arb bushes.The servicing on the petrol car on average is more expensive (tappets and spark plugs every 50k miles = a £1000 service.
blueg33 said:
You need to factor in purchase price and depreciation for the maths to work.
Eg We have a 3.0tdi Audi A6 and a 3.0l petrol Subaru Outback, both the same age with the Audi now on 100k miles and the Outback on 60k miles
The second hand value of both was about the same in 2010, now the Audi is worth about £10-11k and the Outback £7-8k (looking at adverts on the internet).
So that's an extra £1k a year depreciation for the petrol car or 763 litres of petrol. Large petrol engines are not popular with buyers, an Outback with a diesel engine is worth £1-2k more than the petrol.
Outback averages 25mpg, Audi averages 36mpg.
little point in comparing two different cars, if your going to do this properly, you need to compare the same car with different engines..Eg We have a 3.0tdi Audi A6 and a 3.0l petrol Subaru Outback, both the same age with the Audi now on 100k miles and the Outback on 60k miles
The second hand value of both was about the same in 2010, now the Audi is worth about £10-11k and the Outback £7-8k (looking at adverts on the internet).
So that's an extra £1k a year depreciation for the petrol car or 763 litres of petrol. Large petrol engines are not popular with buyers, an Outback with a diesel engine is worth £1-2k more than the petrol.
Outback averages 25mpg, Audi averages 36mpg.
let's face it, Subaru's are s
t on fuel, always have been.how about you compare your Audi with the petrol equivalent? like a 2.0TFSi one?
Colvette said:
I live in Surrey and work in Cheshire (short term thing - new job), and I'm currently commuting on a weekly basis to the place I'm staying. Over the course of my week, I'm doing around 600 miles, and it's costing me a fortune in fuel (2.0TS Alfa GTV).
How short is short term...?If short is anything less than 6 months, the 'man maths' won't stack up for changing to a soot-chucker.
If you are going to be doing this job for 12 months or more, then it could be beneficial to change the car for a diesel.
Scuffers said:
little point in comparing two different cars, if your going to do this properly, you need to compare the same car with different engines..
let's face it, Subaru's are st on fuel, always have been.
how about you compare your Audi with the petrol equivalent? like a 2.0TFSi one?
Thats a fair point, but is the only real comparable I have, in many respects the cars are similar, both 4wd, both tiptronic auto, both same age and same capacity. let's face it, Subaru's are s
t on fuel, always have been.how about you compare your Audi with the petrol equivalent? like a 2.0TFSi one?
I am not sure you can compare a 3.0tdi quattro with a 2.0Tfsi, the 3.2fsi quattro would probably be a closer comparison, but I don't have real life stats for those.
As mentioned by others, there isnt really a general rule, you need to look at your own circumstances, there are multiple variables.
What I do, is decide on the period I am going to own the car over and then just calculate it out. Where it gets messy is when you start compromising on purchase price and/or age etc.
For example, a diesel may work out cheaper but then you realise that if you buy a car 2 years older, then a petrol works, but then thats not a fair comparison!
My head hurts.
What I do, is decide on the period I am going to own the car over and then just calculate it out. Where it gets messy is when you start compromising on purchase price and/or age etc.
For example, a diesel may work out cheaper but then you realise that if you buy a car 2 years older, then a petrol works, but then thats not a fair comparison!
My head hurts.
blueg33 said:
Thats a fair point, but is the only real comparable I have, in many respects the cars are similar, both 4wd, both tiptronic auto, both same age and same capacity.
I am not sure you can compare a 3.0tdi quattro with a 2.0Tfsi, the 3.2fsi quattro would probably be a closer comparison, but I don't have real life stats for those.
how did you work that out?I am not sure you can compare a 3.0tdi quattro with a 2.0Tfsi, the 3.2fsi quattro would probably be a closer comparison, but I don't have real life stats for those.
2.0TFSi is about the same power as the 3.0TDi, the 3.2 FSI is way ahead, comes back to what you call like for like?
either way, if your only getting 35 from the dismal, I get 30 from the supercharged 3.0Tfsi S4, and 5Mpg is not enough of a difference...
blueg33 said:
Mine is 100k in. All that has been replaced is brake discs and pads and arb bushes.
The servicing on the petrol car on average is more expensive (tappets and spark plugs every 50k miles = a £1000 service.
A fair point and of course not everyone is unlucky with these problems. The servicing on the petrol car on average is more expensive (tappets and spark plugs every 50k miles = a £1000 service.
But here's another perspective. Driving a small petrol snotter like I do means you can do most servicing yourself without having to worry about service history.
Here's the costing for that same service:
New headgasket (needs replacing after tappets)about £10
Tappets £30 for labour
New plugs about £10 for a set
Plus I get nearly 40 mpg
blueg33 said:
The servicing on the petrol car on average is more expensive (tappets and spark plugs every 50k miles = a £1000 service.
Tappets? is it 1983? 
I presume you're talking about the TVR- in which case, how is that at all relevant to a modern, mass-produced everyday car?
I spent £131 on parts to perform a more than full service on my 525i. Add a couple of hours labour tops if you don't want to DIY.
Bear Phils said:
New headgasket (needs replacing after tappets)about £10
Tappets £30 for labour
New plugs about £10 for a set
Your car has hydraulic lifters which rarely require any attention at all for the entire life of the car. Also you don't need a head gasket after adjusting valve clearances. Did you mean rocker cover gasket? Tappets £30 for labour
New plugs about £10 for a set
Bear Phils said:
A fair point and of course not everyone is unlucky with these problems.
But here's another perspective. Driving a small petrol snotter like I do means you can do most servicing yourself without having to worry about service history.
Here's the costing for that same service:
New headgasket (needs replacing after tappets)about £10
Tappets £30 for labour
New plugs about £10 for a set
Plus I get nearly 40 mpg
Agreed. I also have a small petrol snotter. But here's another perspective. Driving a small petrol snotter like I do means you can do most servicing yourself without having to worry about service history.
Here's the costing for that same service:
New headgasket (needs replacing after tappets)about £10
Tappets £30 for labour
New plugs about £10 for a set
Plus I get nearly 40 mpg
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