6 or 4 cylinder diesel?
Discussion
I'm currently helping my parents find a new car and after quite a few test drives they have decided on either a Mercedes E Class estate or a Jaguar XF Sportbrake. Whilst they like both cars in seemingly equal measure they aren't sure on which engine to go for in either. Due to my Dad loosing his job through illness a few years ago they were forced to sell their mk2 Focus RS and swapped to a more wallet friendly 1.0 Ecoboost Focus estate. With things now looking up they have decided to get a new car but want to keep the practicality of the estate but move a little more upmarket. They only cover approx. 15K miles per year and my Dad will use the car for business which will involve driving across the city a few times each day. In their current car he gets at best 35-38 mpg; not bumper to bumper traffic but plenty of traffic lights etc. Now, they like the 3.0 V6 diesels in both cars but are concerned they'll get far worse fuel economy than they currently get and wonder whether they should just settle for the 4 cylinder option. Has anyone any experience using either an E350 or XF 3.0d (240) for this kind of driving?
Can't comment on the six cylinders but I'd say that the 4-cylinder diesels would be 10-20% better than the Focus Ecoboost (with the delta increasing on longer trips), while offering broadly similar performance when pressing on (less rev range and more weight offset by more torque).
It really would be a guess but I would think that the six-cylinder diesel would do better than the Focus on long trips but be 10-20% worse on shorter ones, probably meaning that it's a wash overall.
It really would be a guess but I would think that the six-cylinder diesel would do better than the Focus on long trips but be 10-20% worse on shorter ones, probably meaning that it's a wash overall.
http://carfueldata.direct.gov.uk/
It is typical for 4 cylinder engines to be more economical than those with 6 cylinders.
It is typical for 4 cylinder engines to be more economical than those with 6 cylinders.
Edited by herewego on Tuesday 22 July 20:47
Although not the cars you mention I can advise that the latest 5 series gets about 46MPG in 520d form and about 40MPG in 530d (6 cylinder) form for my driving.
Hopefully that'll give you some indication of a 6 v 4 cylinder diesel in a large car. (PS - both the 520d and 530d are 8 speed autos).
Hopefully that'll give you some indication of a 6 v 4 cylinder diesel in a large car. (PS - both the 520d and 530d are 8 speed autos).
Hold on, how many miles will he drive in an average day? Diesel isn't worth it if its short journeys. You'll just wear out the DPF and that'll cost ££££ to replace. Unless your doing high mileage petrol is the way to go.
people buy diesel on the misconception they are cheap to run because of the high MPG but as soon as you start using them for short journeys and stop start traffic you'll soon clog the engine with carbon (older diesels) or damage the DPF as it wont charge properly.
people buy diesel on the misconception they are cheap to run because of the high MPG but as soon as you start using them for short journeys and stop start traffic you'll soon clog the engine with carbon (older diesels) or damage the DPF as it wont charge properly.
If they want to move upmarket, move upmarket. The 4-pot rattlers are aimed at fleet buyers. I despise modern diesels, but if they really need a diesel then the 6-pot will preserve a lot more of the feel and refinement a big, powerful luxurious car should have.
I've only really driven V6s and V8s for the past decade for most of my milage. I got used to them and now they feel normal. I've add the odd 4-pot in and about and you can really feel them shuddering and shaking by comparison. I was shocked at the 2.2d XF when I was picked up in one as part of the dealer's collect/drop off service. As 4-bangers go it's a good engine, but stepping down from more cylinders the 4-pot was conspicuous by its inherent vibration and lack of refinement. No amount of sequential injection and balancer shafts can get away from the fact that there are fewer power strokes per revolution - and it really shows.
Same story for an E60something 520d courtesy car I had. It was ok, but the engine really made the car feel cheap and downmarket.
If coming up from a small, cheaper sort of car someone might think "rubbish" but coming down from nicer engines it is very apparent.
I've only really driven V6s and V8s for the past decade for most of my milage. I got used to them and now they feel normal. I've add the odd 4-pot in and about and you can really feel them shuddering and shaking by comparison. I was shocked at the 2.2d XF when I was picked up in one as part of the dealer's collect/drop off service. As 4-bangers go it's a good engine, but stepping down from more cylinders the 4-pot was conspicuous by its inherent vibration and lack of refinement. No amount of sequential injection and balancer shafts can get away from the fact that there are fewer power strokes per revolution - and it really shows.
Same story for an E60something 520d courtesy car I had. It was ok, but the engine really made the car feel cheap and downmarket.
If coming up from a small, cheaper sort of car someone might think "rubbish" but coming down from nicer engines it is very apparent.
Four cylinder diesels are plain nasty unless you need them for company car tax reasons IMHO. I'm talking 2013/14 models here, based on recent shopping which ended up with a six cylinder diesel, not because of miles but because of availability/resale.
Even in the new S class the 4 cylinder diesel in the hybrid is said to sound rough, and they certainly do in 5 series/A6/E class compared to the sixes. A smooth 4 cylinder petrol with lots of sound deadening can sound acceptable, a 6 cylinder diesel can actually sound nice. If the economics add up, a 6 cylinder petrol is a nice thing, especially if boosted.
Even in the new S class the 4 cylinder diesel in the hybrid is said to sound rough, and they certainly do in 5 series/A6/E class compared to the sixes. A smooth 4 cylinder petrol with lots of sound deadening can sound acceptable, a 6 cylinder diesel can actually sound nice. If the economics add up, a 6 cylinder petrol is a nice thing, especially if boosted.
I have had a 350, 250 and 220. The difference between the 4 and 6 cylinder engines is nearly all in the power delivery. In terms of the mpg I only noticed a couple of mpg difference 38mpg in the 350 and 40mpg in the 250 and the 220. This is a mixed cycle 80 miles a day A road, B road, dual carriageway and a little bit in town.
The V6 is much smoother and quieter and has better power delivery. The I4 is less refined but cheaper to buy.
The V6 is much smoother and quieter and has better power delivery. The I4 is less refined but cheaper to buy.
How about one of the Blue Efficiency E-Classes? Their petrol V6s are very economical and would be more suited to City driving.
Example;
http://www.autotrader.co.uk/classified/advert/2014...
Example;
http://www.autotrader.co.uk/classified/advert/2014...
johnbanks said:
Four cylinder diesels are plain nasty unless you need them for company car tax reasons IMHO. I'm talking 2013/14 models here, based on recent shopping which ended up with a six cylinder diesel, not because of miles but because of availability/resale.
Even in the new S class the 4 cylinder diesel in the hybrid is said to sound rough, and they certainly do in 5 series/A6/E class compared to the sixes. A smooth 4 cylinder petrol with lots of sound deadening can sound acceptable, a 6 cylinder diesel can actually sound nice. If the economics add up, a 6 cylinder petrol is a nice thing, especially if boosted.
4 cylinder diesel or petrol are equally dull unless modified , Even in the new S class the 4 cylinder diesel in the hybrid is said to sound rough, and they certainly do in 5 series/A6/E class compared to the sixes. A smooth 4 cylinder petrol with lots of sound deadening can sound acceptable, a 6 cylinder diesel can actually sound nice. If the economics add up, a 6 cylinder petrol is a nice thing, especially if boosted.
V8 or 5 cylinder for me ,the Volvo 5 pot diesels sound great and go well
Good car too IMHO..
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