Diesel vs petrol

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squizza

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Good afternoon. After my car failing the mot and costing more than it is worth to fix I'm having to get a new motor.

Petrol has always been choice for me, no reason except it's what my parents always chose so I followed suit.

Broad question I am sure; which is better for your buck....petrol or diesel. Also how mant miles can each realistically do before the car goes to car heaven.

Been looking at a diesel golf but my price range means the one's I've seen are quite high mileage already.

Kind regards and thanks in advance
 
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What's your annual mileage (roughly)?
 
Diesel cars demand a premium when buying and unless you are doing lots of miles you may never recoup the mpg advantage of a diesel compared with the extra cost. People how buy diesels tend to be doing a lot of miles as you have noticed while looking at tdi golfs.
 
It really varies from car to car....... the engine may last til 250K miles for example but you might need new injectors after 125K miles.

The choice between a petrol & diesel should really come down to how many miles you do. It used to be 20K+ a year before a diesel worked out cheaper due to them being more expensive to buy/maintain but I don't think it's that much of a problem now.

I went from a 1.8 petrol Focus to a 2.0 diesel Focus nearly 2 years ago. I do roughly 13K miles a year and my fuel bill has dropped from over £200p/m to around £150p/m. Servicing it seems to be about the same, road tax is about £80 cheaper.

Add to that the performance is better and on a long run I can get nearly 60MPG out of it :D

The downside though..... when bits start to break they can get expensive..... my particular engine apparently can have injector problems around 90K-100K miles, you're looking at the thick end of £1000 to fix. I believe my clutch could be on it's way out but you really need to replace the dual mass flywheel at the same time, I've priced it up at £350 in parts alone.

Best thing to do is narrow it down to a few different cars and take a look on Honest John website, or as others have done, ask opinions on here :)
 
Is it round town mileage or short hops? Roughly whats your average journey length
 
Overexposed said:
Is it round town mileage or short hops? Roughly whats your average journey length
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My daily work commute is 30 miles per day, and I probably do about 50-60 miles over a weekend.

Lot of town and A road driving.
 
Just a heads up look at other makes of cars, golfs seem to hold their price so you may get a better deal on a different make with lower mileage.

diesels are not as good performance as a petrol cc equivalent so you will need to up the engine size to get the same sort of performance.
 
£65 gets me 450 miles from my Seat Leon 2.0 TDI (170bhp).

I don't drive my car gently. My last car would do 500 miles on the same money (Skoda Octavia 1.9 TDI) and my sister had the same car and could get 650 miles due to the way she drove.

Diesel vs Petrol performance, are you talking on a track or on the road? I find my diesel more usable and gives easier performance to petrol. Petrol will give the best performance overall, but cornering in 3rd in a diesel allows me to accelerate a lot more than you could in a petrol as you would be in 2nd to be in the right rev range and be on the limiter. Diesel aren't as responsive is the main difference and some extra weight up front.

Not all diesels are equal.

VAG cars (VW, Audi, Seat and Skoda) have 20k or 2 year long life service intervals, Mazdas have 9k or 1 year service intervals.

Makes a big difference over 100,000 miles.
 
A lot depends on the age of the car and which emission standard it is built to. I've had a few diesels in the past and currently have a Skoda Octavia with the 1.6TDI engine built to meet the Euro 5 standard. I had trouble with the EGR (exhaust gas recirculation) valve and DPF (diesel particulate filter) this time last year and if it hadn't been in warranty it would have been well over £1000 to fix. It has never reached the fantasy mpg quoted by the manufacturer and it's the first car I've had where I haven't at least matched their figures, but that still puts it in the mid 50s. At 12k a year I think I'd be going for petrol.
 
I found my 2.0 TDI Focus more expensive to run than my 1.8 Petrol Astra overall. As has been mentioned, Dual mass flywheels, DPF units and tyre wear plus additional servicing costs and very poor MPG in town cost me dearly in the economy stakes. However, I do like teh way a 2.0 diesel just pulls and pulls, my latest 1 yr old Focus is stunning and also very flexible in that it will run up to the limiter easily (my old one wouldnt). I also like its ability to just pootle around when I dont want to drive fast. The new one is better than the old for mpg around town.
If I had to buy an "old" car I'd definitely go petrol as I think the higher mileage diesels will cost a lot to keep running.
 
All Diesels have DPF

The era around 2006 when they first came in had issues as the car wasn't designed to have one.

New ones are.

BUT and this is a big but, you must do a long run every other week or so to burn off all the particles (or whatever they are called) as it only happens when the exhaust temp gets high for a long period of time. You will gt a DPF warning and if you get one, go on a long journey.

If you only do town driving, get a small petrol on the £0 road tax (check out Hyundai i20 for example or Toyota Aygo)
 
Buying new or second hand?

[EDIT: Doh just seen you said a golf with high mileage so obviously second hand]

2nd hand the premium you pay for a diesel over petrol is not so noticable. I only do about 9000 a year and have had 2nd hand diesels for going on 10 years now. I swear it was when I first switched to diesel that suddenly the price of it overtook petrol and stayed there ever since.

Ive just quickly punched 12000 miles into a spreadsheet. for 12,000 miles a year with diesel at £1.41 and assuming 50 mpg fuel cost is £338 per year. For a petrol at £1.37 a litre, giving 40mpg fuel cost is £411. If the petrol gave you 45mpg still costs £365 p.a.

Add in the fact that often the car tax is lower on a similarly powered (or higher even) diesel to a petrol and more savings made there.

Until my last car, all my diesels had over 80,000 on the clock when I bought them. Didnt worry me. And never had to cough up for new injectors. Never had any DPF problems either and do fairly short commute (13 miles each way)

Because diesels often do higher mileages than petrol cars you should get a more recent edition of a car for the same price than you could a petrol. The old adage was, always go for a higher mileage newer car rather than low mileage old one.

2p
 
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Thank you for the feedback so far - it really is appreciated :)

Just out of interest, how are people finding the petrol Golfs mileage wise?

I'll start looking at petrols again I think as I see everyones point :)
 
My decision to go for diesel second time around was solely down to having a paltry 14ppm mileage rate at my previous employer.

I had a TDCi Mondeo about 5 years ago and back then when fuel was well under £1 per litre, and then I wasn't fussed about fuel economy so I went for a Leon Cupra R, which was doing 30-35mpg. However, when fuel prices skyrocketed way above £1.20 per litre then I had to change to an oil burner because I was having to pay my employer money back when purchasing fuel on my company credit card.

When I changed to diesel (a Volvo S60 D5) I went from owing my employer something like 5ppm to breaking even or making the odd penny here per mile.

But, I was doing 35,000 mile per year before at my old place and now I do 500 mile per week minimum just commuting to the office. If I was doing a few miles here and there I doubt diesel would actually be any cheaper, or at least not so noticeable in terms of costings.

I also had the advantage when I changed to the diesel Volvo, that to change cars only cost me £1500 - the Volvo had 80,000 on the clock (it now has nearer 140,000 two years on) and the tax was about the same per year.
 
Petrol. Then you can have a peaceful drive to work instead of a clattery one :)

If you can find a petrol car that can do 50mpg and isn't too asthmatic you will have the same fuel costs as the diesel.

Honda do reasonably quiet diesels though. The citroen HDI engines are also very quiet compared to most diesels.
 
Sarah my wife has a Toyota Rav 4 diesel - its a 4 x4 and manufacturer figures say 45mpg. She uses it round town and gets 27mpg - if we take it out for a run it gets 37mpg.
I had a BMW 330d and over 80000 miles it averaged 40mpg driven hard on long journeys.
My point is don't be taken in by Diesel is more economical - it can be with higher mileages and no stop start driving but the new petrol engines a frugal, clean and low emissions and with your mileage there may be nothing to choose between the two. Drive them both Diesels drive differently to petrol - if its a small car you want, petrol may be better, larger like a bigger hatch or people carrier diesel may be better too. remember too Diesel is more expensive than petrol both to buy the fuel and the car. Good Luck
 
Dale_tem said:
£
Petrol will give the best performance overall, but cornering in 3rd in a diesel allows me to accelerate a lot more than you could in a petrol as you would be in 2nd to be in the right rev range and be on the limiter.
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How fast do you go round corners?

If i hit the rev limiter in 2nd and i'm not on a motorway then i'm speeding.
 
Rev limiter in most petrol cars for 2nd is under 60mph.

So Any national speed limit A road will be under that.
 
Overexposed said:
Sarah my wife has a Toyota Rav 4 diesel - its a 4 x4 and manufacturer figures say 45mpg. She uses it round town and gets 27mpg - if we take it out for a run it gets 37mpg.
I had a BMW 330d and over 80000 miles it averaged 40mpg driven hard on long journeys.
My point is don't be taken in by Diesel is more economical - it can be with higher mileages and no stop start driving but the new petrol engines a frugal, clean and low emissions and with your mileage there may be nothing to choose between the two. Drive them both Diesels drive differently to petrol - if its a small car you want, petrol may be better, larger like a bigger hatch or people carrier diesel may be better too. remember too Diesel is more expensive than petrol both to buy the fuel and the car. Good Luck
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I totally get your point but.......

My 2.0TDCI focus is a fair bit quicker than my old 1.8 Focus yet I still get 10MPG more on a weekly basis for my daily commute and "general" driving (42MPG vs 30MPG).

On a long run I'd be lucky to get 40MPG out of my old car but can get 50MPG plus from the diesel.

I'll accept the point that my old 1.8 was an X reg so not very comparable to newer petrol cars but the guy who sits next to me at work has a year old 1.0 Ecoboost Focus and has more or less the same commute as me, he just about gets 40MPG, says the performance is a little lacking although he probably wouldn't give Miss Daisy a run for her money :lol

We're looking to replace the wife's Pug 107 soon as we're looking to start a family and it won't be that practical, road tax is about £30 a year and if does 50MPG+ even on short runs but she only does 3K-4K per year. Whether we get a small diesel or petrol is still under debate, I'm thinking small petrol give then lack of mileage
 
If you can afford it buy whichever engine type you want and to pot with your mileage! it's as much about the driving experience as anything else (assuming the car isn't just a box on wheels that gets you from A to B in your mind).
In my case it was a no brainer, the car I own came in two engine choices, a 1.6ltr petrol or a 1.5ltr diesel, the diesel is stronger, cleaner, more economical and more responsive, it also costs considerably less to tax.
 
srichards said:
Petrol. Then you can have a peaceful drive to work instead of a clattery one :)
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You jest surely. That old chestnut went out in the 80's I thought. Modern diesels no noisier than any other car. And the tyres being more expensive because you have to get em from Massey Ferguson, etc etc.

If you can find a petrol car that can do 50mpg and isn't too asthmatic you will have the same fuel costs as the diesel.
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Ah but a 50mpg petrol car will probably be less than 100bhp job. An equivalent diesel then will probably give you 60+ mpg and likely be £0 "car tax".
 
squizza said:
Just out of interest, how are people finding the petrol Golfs mileage wise?
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Sarah have a look at THIS website for lots of real world MPG figures.

David
 
Generally the diesels are a little more expensive than the petrols - as you've found out - higher mileage diesels than petrols in your price range.

The higher mileage diesels will also need maintenance on other parts of the car before the lower mileage petrols (wheel bearings/shocks etc - assume they have a certain mileage lifetime on the same car - a higher mileage diesel will get to that point quicker). Having said that if the miles are motorway miles then it might be better than a lower mileage petrol.

As for the noise of diesels, we dont know what your budget is as yet - but I can say without shadow of a doubt that there are some quiet diesels out there - and some that still sound like tractors (BMW M47 and N47 engines for example).
 
On an older car I'd go with a petrol every time

You may be fine but a DPF , injector or Turbo fault would kill any fuel savings made over the next 2 years

As an example a car doing 100 miles at 35 mpg would cost £16.76 @£1.29 per litre, a diesel doing 50 mpg at £1.35 per litre would cost £12.27 £4.49 cheaper

At 12,000 miles a year that works out at roughly £530 less

Factor in a turbo at £600, DPF £600 , Clutch and dual mass flywheel £600 , injectors £600 plus the premium you'd pay for a diesel a petrol car makes much more sense

Plus bigger engines can go for buttons, I bought a Renault megane with a 2.0 petrol engine for £3,700 a couple of years ago, it'd done 14,000 miles, one owner and was a week over 3 years old
 
My Skoda did 150,000 miles, only main thing that went wrong was the gearbox at 135,000 miles.

Flywheel and clutch were both fine. DPF weren't in at that time, but if you do long runs, a DPF shouldn't be an issue either.
 
There will likely be little performance difference between diesel and petrol in real world terms. Petrol will be quicker off the line but a similar sized turbo diesel engine will leave the petrol engine powered car behind on overtaking manoeuvres. When you put your foot down in a petrol, it will use up the fuel a lot quicker than the diesel will.
DPF's are on Euro5 emission diesel cars most were introduced in 2007, very few had them before that. A lot of DPF's can be eliminated by a simple remap.
I have a Mondeo ST TDCi 153bhp as standard it has returned 55-60 mpg on a mixture of A roads, B roads, and motorway. It now has a few engine modifications with remap and produces 190 bhp, it feels more like a petrol engine to drive but still returns 53 to 58mpg, it would probably return more. but I like to give it some. ;) The engine doesn't clatter neither and it's just coming up for 100k miles. The petrol equivalent the ST220 is still quicker off the line, but not when accelerating from say 3rd gear or above. But at best the ST220 will only return about 24mpg and if you drive it hard, it is possible to get it down into single figures. This is more of a "performance" model comparison but still relates to smaller less powerful engine cars.
I've driven 1.6 TDCi versions of the Ford Fusion and previous style Fiesta which would have been pre DPF models and again they were very responsive at overtaking, especially on motorways or A roads.
Diesels are likely to be lower insurance groups also.
Your best bet would be to test drive similar models in petrol and diesel variants to see how you like them. Can't say I've ever noticed diesel engine cars being less economical when used around town, than the petrol engined equivalent.


I had my dual mass flywheel and clutch replaced at 90k, but that was only because I killed the slave cylinder which in turn leaked onto the clutch, the flywheel didn't need replacing at that time, but as the clutch and slave cylinder was being done, it made sense to save on labour when it would need doing and have it done at the same time. If I hadn't killed the slave cylinder, I'd have got many more thousands of miles out of the flywheel. A workmate had his flywheel replaced on his Mondeo at over 180k miles.
 
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When Dad was alive, he had a 1600 Diesel and I had the same size petrol. Both Citroen Xsara Picassos. His was faster, more frugal and handled better than mine (same age and mileage). Not sure how the maths would have worked out over 3 years but he paid about £1500 premium for the Diesel over the petrol.
 
it's hard work trying to pick a good second hand car it seems the build quality nowadays is not what it used to be

i think everything has been said about the petrol / diesel dilemma but if you intend to keep the car over long term i prefer a diesel

don't be tempted by a an A class merc
nice to drive and lots of room for a small car but when they go wrong ( and they do go wrong ) the cost of repair is expensive
doesn't matter if it's petrol or diesel apart from the injector pump on the diesel which are known to leak ) the common faults are the same
 
I would go for a petrol at that mileage something with a small petrol engine will be economical on fuel and be cheap to run
I was told that if a diesel engine is run on petrol by mistake it causes damage and it's never the same again, im not sure if this is accurate tho:)
 
My current honda civic was my first diesel and ive now had it for nearly 6years and much prefer the characteristics of a turbo diesel. Lots of torque for easy overtaking and 60+mpg on a steady run. Now its had a remap, ,uprated clutch and smf conversion 205bhp and 315 f/lb of torque it firkin quick and can still get 60+mpg.
 
Sarah I was in the same position when my old Golf went for a service and I was told it was going to cost a fortune to get through the MOT
I looked at newer golfs and the Seat Leons caught my eye, same car but half the price , had mine 3 years now and it's been great.
 
LCPete said:
I would go for a petrol at that mileage something with a small petrol engine will be economical on fuel and be cheap to run
I was told that if a diesel engine is run on petrol by mistake it causes damage and it's never the same again, im not sure if this is accurate tho:)
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Having only driven petrol cars, I managed to put unleaded in my diesel focus :bang:

Luckily I realised this after only 8 litres. The tank was nearly empty so I brimmed it with diesel and kept topping it up as soon as I'd used 1/4 tank.

It seems that no harm was done and I've heard of people in cold contries *having* to put a small amount of unleaded in the tank of diesels to stop the diesel 'waxing'.

Major damage can be done if you fill a diesel with unleaded and drive away from the pump. The fuel itself acts as a lubicant for the diesel pump and unleaded can cause the pump to sieze.
 
Dale_tem said:
All Diesels have DPF

The era around 2006 when they first came in had issues as the car wasn't designed to have one.
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Sorry, but you are very wrong.
VAG PD engines fitted to cars as late as 2010 did not have the dreaded DPF. There are many Skoda owners who are very thankful about this;)
 
andy700 said:
Sorry, but you are very wrong.
VAG PD engines fitted to cars as late as 2010 did not have the dreaded DPF. There are many Skoda owners who are very thankful about this;)
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All new diesels have DPF and most from around 2008 have DPF

So Not very wrong, I was trying to point out the effect of a dpf and they should be wary and understand what it means.

I owned a VAG diesel with out a dpf, a friend had a put diesel from the same year which had a DPF.

It depends how indepth they want to go, best to assume they have a dpf and understand how it must be used.
 
Just my 2p's worth. I've just changed to a diesel at no extra cost. I now run a Clio Sport Tourer as my daily drive (2011). I get 700 miles out a a 50l tank (about £70 till fill from 'dry') with roughly 60mpg average.

I'm saving a huge amount on fuel compared to both my 2.0 and 1.2 petrol cars!

Plus, it has bags and bags of torque which makes it even more effortless to drive than my old 2 litre petrol.
 
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With the miles you're doing i would stick with petrol.
 
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