Diesel V Petrol ???

[Value Motering]

From most of my memory, Diesel has been cheaper and done better MPG.

But now Diesel costs more and Petrol MPG is getting much better.

Take into account Diesel cars are often more money to buy and fix.

I wonder if we will see the decline of Diesel sales and rise of Petrol cars in the near future ???

I am in the process of finding and buying a suitable CLS at the moment, I never thought I would consider a Petrol, but if one comes along and the price/spec is right, I may buy it !!! I have had Diesels for years, never thought I would consider a Petrol again.

I wonder what the price split between Diesel and Petrol will be in the Uk over the coming years ??? 7/9% maybe.... ????

 

[Dieselman]

I wonder what the price split between Diesel and Petrol will be in the Uk over the coming years ??? 7/9% maybe.... ????

Fuel cost or vehicle purchase cost?

 

[Deleted member 37751]

I started to think this way but I think when you sit down and work out the real-life mpg figures, the diesels are far superior.
Add into the mix residuals and you can see why diesels are so popular. Not so much better, just popular....

 

[st4]

Diesel costs about £6.20/gallon, petrol £5.80

So there is under 10% difference in the cost of fuel. A diesel typically out performs a petrol car by 30% on MPG.

No brainer.

Diesels, particularly in the Mercedes market, are much more plentiful so do not really comand much of a price premium. At the new car stage, the petrol and diesel cars cost the same, engine size being considered.

 

[timskemp]

Real world costs are key, and for the same car with similar power output I would expect a diesel to be 25 to 50% better on fuel by volume, which is how we buy it.

Given that the % difference between the price of diesel and petrol gets smaller as the price goes up the advantage is swinging more to diesel.

I averaged 34-37 mpg in the 180bhp E270, 21-24mpg in the 180bhp Volvo S60. Let me put that into context.

I tend to keep my cars for 100k miles, that's £16000 in a diesel car at 37mpg and £1.35/l, or £26000 in a petrol car at 24mpg and 1.30/l.

10 grand in my pocket thank you very much. In fact driving the petrol car is like volunteering to pay 8000 quid more tax than you need to.

 

[Dryce]

So there is under 10% difference in the cost of fuel. A diesel typically out performs a petrol car by 30% on MPG.

No brainer.

Problem with this statement is that I see diesel figures posted here that don't look quite so good. And diesel seems to get hit disproportionately in winter.

Maybe part of the problem is that a % of owners buy diesel for performance rather than economy (not mentioning any names - ahem).

 

[renault12ts]

From most of my memory, Diesel has been cheaper and done better MPG.

But now Diesel costs more and Petrol MPG is getting much better.

Take into account Diesel cars are often more money to buy and fix.

I wonder if we will see the decline of Diesel sales and rise of Petrol cars in the near future ???

I am in the process of finding and buying a suitable CLS at the moment, I never thought I would consider a Petrol, but if one comes along and the price/spec is right, I may buy it !!! I have had Diesels for years, never thought I would consider a Petrol again.

I wonder what the price split between Diesel and Petrol will be in the Uk over the coming years ??? 7/9% maybe.... ????

You have a short memory. Diesel has been dearer than petrol for more than ten years. Since 1996 in fact.

 

[Deleted member 37751]

From most of my memory, Diesel has been cheaper and done better MPG.

But now Diesel costs more and Petrol MPG is getting much better.

Take into account Diesel cars are often more money to buy and fix.

You have a short memory. Diesel has been dearer than petrol for more than ten years. Since 1996 in fact.

 

[st4]

Problem with this statement is that I see diesel figures posted here that don't look quite so good. And diesel seems to get hit disproportionately in winter.

Even in the winter weather my E320cdi will be more frugal than an E350CGI in summer.

The diesel figures are not bad, just not as good as what the manufacturer tells you.

I usually comfortably beat the combined figure, 44mpg on way to work. It books at 37mpg.

The fact it cracks 60mph in under 7secs and wafts along at 155mph is brilliant.

And there is a performance bonus, the mid range torque in a 6pot diesel is like that of a V8 petrol.

Maybe part of the problem is that a % of owners buy diesel for performance rather than economy (not mentioning any names - ahem).

Thats a more recent trend, as the technology in diesel cars enhances, they get quicker.

Diesel winning lemans, never would have thought....

 

[Dryce]

I averaged 34-37 mpg in the 180bhp E270, 21-24mpg in the 180bhp Volvo S60. Let me put that into context.

My 170bhp E240 slug - 29 - 33 mpg over the last year.

10 grand in my pocket thank you very much. In fact driving the petrol car is like volunteering to pay 8000 quid more tax than you need to.

Well my car cost about £3K less than an equivalent age/spec E220 when it was bought. Probably about £6K to £7K less than a E270.

So the fuel would still be a bit in your favour but not as much as the initial purchase price gap which pulls it back in mine. And then the cost of spark plugs and higher resale may well push it back to you!

 

[st4]

My 170bhp E240 slug - 29 - 33 mpg over the last year.

I wager you do not do much town driving, or that you are a very good smooth driver.

Well my car cost about £3K less than an equivalent age/spec E220 when it was bought. Probably about £6K to £7K less than a E270.

I honestly would not think that, I went into MB Glasgow and there was an E240 for sale for about £2k less than my last E220cdi, but it done 20k more miles and had even less spec.

E500's/E350s seem to cost about the same as my current car.

So the fuel would still be a bit in your favour but not as much as the initial purchase price gap which pulls it back in mine. And then the cost of spark plugs and higher resale may well push it back to you!

Entirely mileage dependent. I cover aabout 30k/yr so drop of 10mpg I would notice a lot, plus the hassle of having to fill it up more.

You have sparking plugs, I have turbos, EGRs, injectors all to go wrong. The reliability of a naturally aspirated petrol engine tips it in your favour.

 

[Value Motering]

I guess we need to take account of so many items.

1. Price, buying, servicing, selling of car.
2. Actual MPG for user and miles done during ownership.
3. Insurance, VED, company car tax charges, congestion charges.
4. Noise of engine, diff in feeling/performance of Petrol V Diesel.

I nearly purchased a Golf TSI 1.4 Petrol a few years ago, it was a very nice car, Diesel was much better MPG, but after looking at use/miles/costs, I purchased a 1.6 FSI, on balance it appeared the best choice, looking at all the data so far, the 1.6 was the overall best option for this cars use.

For interest, the Golf 1.6 does many short trips and prob only 5k miles per year.

 

[Dryce]

I wager you do not do much town driving, or that you are a very good smooth driver.

Slugs tend to move smoothly at all times.

It's a Dryce combined figure. Mostly suburban - with a bit of motorway/dual carriageway - and a bit of urban. I'm able to avoid rush hour by flexing my hours. I avoid short journeys.

I think driving styles suit different cars.

I have had no problem beating the manufacturers' figures combined on a day to day basis and on long journeys can beat extra-urban on some cars. But others (eg. Ford Fiesta 1.6 auto and Prius) have been disappointments and I've never got near the manufacturer's extra urban numbers.

With the E240 I can beat the combined figure with care but on long journeys I've never been able to get close to the extra-urban figure without a strong prevailing wind to help - and even then I've never actually matched it.

 

[st4]

Its got 170bhp, at full power, i.e. kickdown, max RPM, it wont be sluggish, but at lowish engine speeds it might be a bit low.

On a 320cdi you'd find it moves smoothly, and you'd have to spank the **** of it to make it go as low as 30mpg.

 

[Dieselman]

I have had no problem beating the manufacturers' figures combined on a day to day basis and on long journeys can beat extra-urban on some cars. But others (eg. Ford Fiesta 1.6 auto and Prius) have been disappointments and I've never got near the manufacturer's extra urban numbers.

With the E240 I can beat the combined figure with care but on long journeys I've never been able to get close to the extra-urban figure without a strong prevailing wind to help - and even then I've never actually matched it.

That's probably because you do less stop start town journeys so gain when a car on the official test cycle would be sitting idling and achieving zero mpg.
as you say, you don't achieve the extra urban figure, which is mainly on the moving part of the test cycle.

A Prius in particular would therefore be difficult to beat as when it's sitting stationary it uses no fuel at al, so if you fall behind when travelling you can't catch that back up.

 

[st4]

A Prius in particular would therefore be difficult to beat as when it's sitting stationary it uses no fuel at al, so if you fall behind when travelling you can't catch that back up.

Do they not also do part of the test on full electric. I cannot remember the timing of the test, but if you do a longer run, a lesser proportion of it will be on electric power so it will never have a prayer.

Thats not to say a prius cannot be economical, just not as economical as Toyota would like you to believe.

PS

My car

Facts At A Glance
CAR: Mercedes E320 CDI
PRICES: £36,895-£38,695 - on the road
INSURANCE GROUP: 17 CO2 [g/km]: 194g/km
PERFORMANCE: [4dr] 0-60mph 6.8s/ Max Speed 155mph
FUEL CONSUMPTION: [4dr] (urban) 26.7mpg/ (extra urban) 47.1mpg/ (combined) 37.2mpg
STANDARD SAFETY FEATURES: Twin front and side airbags, windowbags, ABS, ESP, Brake Assist
WILL IT FIT IN YOUR GARAGE?: Length/Width/Height, 4795/1799/1439mm (saloon)

Have actually achieved extra urban on what would be defined as an extra urban run.

 

[Dryce]

It's party trick is to waft people around staying under 3000.

Its got 170bhp, at full power, i.e. kickdown, max RPM, it wont be sluggish, but at lowish engine speeds it might be a bit low.

Things get a bit raucus above 4000. But we don't admit to that.

 

[Dryce]

A Prius in particular would therefore be difficult to beat as when it's sitting stationary it uses no fuel at al, so if you fall behind when travelling you can't catch that back up.

But they quote an extra-urban number for the Prius ..... which is presumably requires some movement.

My experiences were with the previous model. I found it was stuck in the mid 40s mpg on routes where I would get low to mid 40s out of a 1.4 litre automatic hatch.

I've no doubt that it will do well in relative terms in persistent stop-start conditions but as soon as it gets out of those it loses its advantages. The discrepancy in the real life experience and stated combined/extra urban numbers was disappointing and IME undermined it.

 

[Dryce]

Do they not also do part of the test on full electric.

I've always been suspicious that they start off the tests with a fully charged battery.

 

[Dieselman]

I've always been suspicious that they start off the tests with a fully charged battery.

Wouldn't you?