Diesel or Petrol?

[Babylon]

Two identical 2nd hand vehicles (small 4WD) from different dealers:

A - Petrol 2004 97,000m (12,000pa) £4,000 (tow-bar fitted, use unknown)
B - Diesel 2005 120,000m (20,000pa) £6,000

Make and model highly-regarded for reliability, drive-quality, etc,. Equipment etc virtually the same in both vehicles.

Deisels not very common because fewer were made at the time. Difference in published fuel economy:

Petrol - 24 urban, 37 extra-urban, 31 combined
Diesel - 35 urban, 48 extra-urban, 42 combined.

I average 12,000m a year, mainly rural and trunk roads, and motorways, with a bit of town driving but rarely in cities. Intend to keep the vehicle for at least five years, and prefer quieter-running and less-polluting petrol engines.

What is the financial logic in buying the higher-mileage, more expensive diesel?

 

[ostell]

Your car tax will probably be lower for the diesel, 120,000 is "just run in" for a diesel, less pollution with a diesel (hence lower tax), less to go wrong with a diesel, 30% better fuel consumption.

Once you're moving the noise is not noticeable. Last 4 cars have been diesel.

 

[Tranona]

That is a big premium (50%) for a diesel. When new the premium is often only 10%. In cash terms fuel savings (if you get the theoretical consumption) is around £600pa - so just over 3 years to get your extra cash back. The diesel may of course have a higher value at the end, but difficult to predict values ahead on a 10+ year old 180000 miles vehicle will be. The diesel may well be more expensive to service and not so pleasant to drive.

At that age and mileage both are potential money pits.

 

[Babylon]

That is a big premium (50%) for a diesel. When new the premium is often only 10%. In cash terms fuel savings (if you get the theoretical consumption) is around £600pa - so just over 3 years to get your extra cash back. The diesel may of course have a higher value at the end, but difficult to predict values ahead on a 10+ year old 180000 miles vehicle will be. The diesel may well be more expensive to service and not so pleasant to drive.

At that age and mileage both are potential money pits.

Agree on £600/yr = 3yrs to recover difference.

My last two cars were older 2.0litre petrol Merc estates bought relatively cheaply at around 90,000 miles - both became money pits at around 16yrs of age or 160,000m, although I did use them hard for five years each (eg extended middle-age crisis driving, carrying 12 cubic foot of oak on roof-rails, etc).

The car I'm looking for now is the Honda CR-V, which appear to have an excellent rep for reliability.

 

[sarabande]

you can quite legitimately stuff cooking oil into the diesel car - up to 2000 litres each year - mixed in with ordinary road diesel. Currently Tesco are selling 5 litre bottles for £4.50.


You know it makes sense , as they say

 

[David2452]

There may be a 30% difference in consumption but petrol is now around 10% cheaper which eats into the miles per £ numbers and reduces the £600 PA fuel difference materialy. My last three cars have been diesel but with the modern petrol consumption numbers, cost diferential on otherwise identical mdels, the milage I do etc I am leaning toward a return to petrol as it may well actually save me money.

 

[ditchcrawler]

Just bear in mind that it is unlikely that you will ever get the published mpg for either car.The published mpgs are obtained from testing on rolling roads in almost laboratory conditions.This was explained to me by an engineer in the car production business.The published mpgs are so you can do a comparison between various cars.However I have got close to the published mpg for my diesel mondeo.However I drive very carefully as I am a retired old git and usually do not require to get anywhere urgently(except on a long journey when I need the loo,the age thing you know)

 

[ostell]

I was really surprised at the consumption on this current car. First trip "Oop North" had it returning 55 mpg for a trip up the M1. 1.9 litre turbo diesel (and I don't hang about on that trip). 500 miles and more to the tank.

I find Diesels are easier to drive, the engines are much more tolerant. I have trouble now when I drive a petrol engine.

Lot less needs to be serviced on a diesel. No plugs, points etc. timing to adjust. What do you service on your (diesel) inboard?

 

[Skylark]

Two identical 2nd hand vehicles (small 4WD) from different dealers:

......prefer quieter-running and less-polluting petrol engines.

Sounds like you're mind is already made up?

I'd hazard a guess that both cars carry an equal risk of requiring a major service item in the next 5 years.

Why do you think a petrol engine pollutes less than a diesel? Exhaust pipe emissions will be water, CO2, unburned hydrocarbons, particulate matter and oxides of nitrogen.

A diesel will burn less fuel for a given distance. A diesel has very little unburned hydrocarbon (air-fuel ratio is generally in excess of stoichiometric (approx 14.5:1)), whereas a petrol engine, at higher loads, uses fuel to cool the whole gas exchange process. A petrol engine at 14:1 would give an exhaust gas temperature well over 1000 deg C. There aren't many readily available, low cost materials able to cope with such extremes. At max power, the a/f ratio has to be reduced to keep temperatures down to about 850 deg C. This is for turbo engines. Don't know much about lean burn gasoline, never really came across them.

As for noise, true, from outside the vehicle a diesel is noisier. However the vehicle manufacturer would have spent a lot of money on sound deadening inside the vehicle for the comfort of the occupants.

As others have said, the overall driveability of a diesel is far better than a petrol, but I guess that's a somewhat personal and subjective view.

Whatever you buy, I hope it turns out a good 'un.

 

[Aground]

Hi,
I have owned two CR-V's: a 2005 petrol and I now have a 2006 diesel so I can hopefully add something useful to the discussion. I had the petrol version from new and put 90,000 miles on it before it was written off by a delivery van. It was a great car and had very few faults (defective engine mounting fixed under warranty, noise from the rear diff that was easily cured with a diff oil change and after 85,000 miles the water pump bearings got noisy and were replaced). I used to get 31pmg driving mostly on 60mph roads with a worst-ever of 23mpg at French motorway speed and a best-ever 37mpg. I think the petrol engine is great but could do with more torque at low revs and I often wished for a 6th gear for the motorway.
The diesel version I now have has 60,000 miles on it an has averaged 42.3mpg over the last 10,000 miles with a worst of 38mpg (French motorways again) and a best of 50mpg. I prefer the diesel to drive over the petrol as it feels more powerful and the extra gear makes it a bit more relaxed on the motorway. The are tales of early clutch failure on the diesel and apparently this can be expensive if it takes out the dual-mass flywheel at the same time. I've no experience of this so fingers crossed!

As a final point, although the 'experts' say that the CR-V is no match for a heavy 4x4 in the rough, I use mine to pull a 16ft Orkney up a pebble beach with no problems and they are really (surprisingly) good in snow.
Hope this helps!

 

[BoyBlue49]

Diesel every time

Diesel engines are now nudging the 500,000 mile mark whereas petrol engines at best will manage half that (personal experience).

Less servicing expense, more mpg, less to go wrong, more reliable, I could go on but you probably get the point.

Good luck with your choice, I don't think the difference in purchase price comes in to it.

 

[the_branflake]

If that's Hondas 2.2 diesel then its a good unit although i also had heard about clutch issues, next doors 06 civic being one of them.

In general i find it easier to achieve a better mpg figure in a diesel car than i do in a petrol, so for me it would be the diesel.

I wouldn't put cooking oil in a common rail engine if it is that one. I've run on it for years in old school diesels (as i am now) but the new ones have too many sensors and can be a bit picky.

 

[Babylon]

Sounds like you're mind is already made up?

I'd hazard a guess that both cars carry an equal risk of requiring a major service item in the next 5 years.

Why do you think a petrol engine pollutes less than a diesel?

...

As others have said, the overall driveability of a diesel is far better than a petrol, but I guess that's a somewhat personal and subjective view.

Whatever you buy, I hope it turns out a good 'un.

Thanks for this, especially correcting my preconception that diesel is more polluting.

I haven't really yet made my mind up, although I'm now thinking of pushing my budget a bit and only buying an example of either engine type with under say 80,000 on the clock, and - if my financial prospects improve within say three years - then I'll trade up to something younger

 

[jwilson]

I was really surprised at the consumption on this current car. First trip "Oop North" had it returning 55 mpg for a trip up the M1. 1.9 litre turbo diesel (and I don't hang about on that trip). 500 miles and more to the tank.

I find Diesels are easier to drive, the engines are much more tolerant. I have trouble now when I drive a petrol engine.

Lot less needs to be serviced on a diesel. No plugs, points etc. timing to adjust. What do you service on your (diesel) inboard?

I like driving a big diesel auto, but many car diesel engines now are remarkably complex, and repair costs can be high for dual-mass flywheels, diesel particulate filters, electronically metered multi-burst injection systems etc. One failure can easily write of the cost of a lot of petrol.

A modern car diesel is not a simple low-revving lump like a marine diesel, or even a typical 10-15 year old car diesel. Petrol engines are now simpler and cheaper to repair than most modern diesels.

 

[Babylon]

Hi,
I have owned two CR-V's: a 2005 petrol and I now have a 2006 diesel so I can hopefully add something useful to the discussion. I had the petrol version from new and put 90,000 miles on it before it was written off by a delivery van. It was a great car...

I think the petrol engine is great but could do with more torque at low revs and I often wished for a 6th gear for the motorway.

...I prefer the diesel to drive over the petrol as it feels more powerful and the extra gear makes it a bit more relaxed on the motorway. The are tales of early clutch failure on the diesel and apparently this can be expensive if it takes out the dual-mass flywheel at the same time. I've no experience of this so fingers crossed!

As a final point, although the 'experts' say that the CR-V is no match for a heavy 4x4 in the rough, I use mine to pull a 16ft Orkney up a pebble beach with no problems and they are really (surprisingly) good in snow.
Hope this helps!

It certainly does help, thanks, especially the drive and consumption comparison between the two engine types.

I'm not looking to pull my 4,500kg boat home, nor go much more off-road than some NT car park, but its good to hear feedback also on the CR-V's snow performance, which is quite important as I live in the sticks.

 

[E39mad]

you can quite legitimately stuff cooking oil into the diesel car - up to 2000 litres each year - mixed in with ordinary road diesel. Currently Tesco are selling 5 litre bottles for £4.50.


You know it makes sense , as they say

Don't try it with modern common rail "high pressure" diesels - you will wreck it

 

[E39mad]

Your car tax will probably be lower for the diesel, 120,000 is "just run in" for a diesel, less pollution with a diesel (hence lower tax), less to go wrong with a diesel, 30% better fuel consumption.

Once you're moving the noise is not noticeable. Last 4 cars have been diesel.

Less to go wrong with a diesel - don't think so if it is modern diesel with turbo, high pressure pumps, injectors, dpf, egr valve's, crankcase breathers etc etc - they are complex pieces of kit and particularly Renault/Fiat/Vauxhall have has a lot of issues recently even under warranty.

 

[CreakyDecks]

I'm guessing that if you keep your cars for five years and are looking at 2005 cars then your present one is pre 2001. If so, be prepared for a big shock when you come to tax your new acquisition! A lot of 4x4's are in band M, which is £450 a year!

 

[Boathook]

Less to go wrong with a diesel - don't think so if it is modern diesel with turbo, high pressure pumps, injectors, dpf, egr valve's, crankcase breathers etc etc - they are complex pieces of kit and particularly Renault/Fiat/Vauxhall have has a lot of issues recently even under warranty.

You missed the particulate filter on the exhaust system. £600 to replace when it goes and they do. I have a company diesel at present and if I was to have a private car it would be petrol.

 

[E39mad]

You missed the particulate filter on the exhaust system. £600 to replace when it goes and they do. I have a company diesel at present and if I was to have a private car it would be petrol.

Sorry should have expanded my post: dpf is diesel particulate filter. I run an older diesel from 2003 - luckily it doesn't have a dpf, have bypassed the egr valve, change the vortex breather for a more modern version less likely to clog with oil and do intermediate oil services - had it from 6 months old and so far all has been fine. Wouldn't have the more modern version without a decent warranty.