Diesel cars vs. petrol (Benzin)

Hi All:
I am planning to buy a used car this coming month and I have not make my mind between a diesel or regular gasoline engine. Could you please advice what will be a good choice considering that I will probably do about around 20,000 km a year. Need to explore new places you know.

Thanks

Diesel every time. Diesels are more economical (especially cruising long distances at 130+mph), diesel is cheaper (although road tax for a diesel is slightly it'll pay for itself in no time), diesel engines last longer and nowadays performance is comparable with that of a Petrol. I can't for the life of me think why people drive petrol cars unless they've got money to burn.

i think diesel is more effcient and burns slower but mite cost slightly more.

Diesel cars do cost a grand or so more (brand spanking new I mean) but they will more than make up for that during their lifetime. They are more efficient. Diesel doesn't burn 'slower', whatever that means, but [speccy twat mode/on] diesel engines have a higher compression ratio (usually about 1:16 compared to 1:8 for a petrol) which ignites the fuel without the need for a spark plug despite it being a heavier oil and less prone to explosive combustion [speccy twat mode/off]. I imagine this will be of no great concern to you.

no breakers, coil or h.t. leads can go wrong on a Diesel, they are better in the cold and damp conditions. Diesel doesnt use spark plugs, so thats one less expense.

Turbo charging a diese engine car is a lot easier than a petrol engine, as its easier to push as much air as required into the compression area.

If Petrol engine is started when the weather is cold it will need a lot of fuel to make it run properly, the difference for cold -> warm for a diesel is not that much, so for short trips a Diesel is better than a petrol as well.

Disadvantage of a diesel is that it will have less power than a equivalent petrol engine, unless you buy a turbo diesel engine, that will give same power (well near enough) and better fuel economy.

Diesel's sound like tractors <- enough said

Diesels good for towing as all torque is produced at low revs but they are crap for a 0-60 mph sprint (or 0-100 km/h ).

Diesels are not as good for handling as a petrol as the engine itself weighs more, thus affecting the steering as well, so make sure you get one with Power Steering if you do get one.

Personally I would for a petrol, probably cos I am addicted to speed

But I hope that helps you mate

Personally, I can't stand diesel. The stuff stinks – you have to wash your hands thoroughly after filling the tank. Even worse than the smell is the noise - the engine sounds like a gasoline engine that is just about ripe for scrap – I mean it's simply not pleasant/esthetical.

As for performance: Nowadays on the Autobahn I come across the odd diesel limo that has made it into the 250 km/h league – nonetheless, all I have to do is wobble with my toe to put them in their place

Diesel is fine for commercial vehicles I guess, but no way I would put up with that noise/smell in my private car.

also check if the diesel car you are looking at is suitable for Bio-diesel. Some are , some need slight modifications. Bio-Diesel is around 20 cents a litre cheaper than standard diesel.

They did a little maths on an edition of "Top Gear" in the UK. They reckoned there was nothing much in it, whether buying new or 2nd hand. The diesels all cost x percent more than the equivalent petrol, and whilst you get better fuel economy it takes quite a long time to get the extra cash back if you do average mileage.

I know they are getting better all the time - but I wouldn't fancy a diesel myself - they sounds like taxis.

Doesn't the German gov't tax diesels at a higher rate due to them being dirtier?

yeah, the maths here are slightly different, since fuel tax on diesel is considerably lower here than in the UK but vehicle tax (Kfz-Steuer) higher (than petrol cars, whereas in the UK they are the same). Service costs are higher than petrol engines in both markets.

This means the fixed costs (Kfz-Steuer, servicing, higher purchase price) make diesels costly for low mileage drivers.

The last time I did a calc, the break-even came out at about 15-16.000 km per year. After that you are laughing all the way to the bank.

Bear in mind that the road tax (Kraftfahrzeugsteuer) on diesel engine is 50% more than petrol. On a 2 litre engine that's €150 a year extra. Even with 25cents a litre price difference that's a lot to make up. Although the diesel engine is principally simpler, new developments such as common rail injection and turbo complicates things, such that diesels usually need more regular trips for service...

If considering costs alone, the usual break-even point for petrol over diesel is around 20-25,000km a year... The ADAC publishes an annual comparison over 450 similar diesel/petrol models. If youare an ADAC member you can download it here. If you're not a member tell me the car model you are looking at and I'll dig out the comparison

YL6

Source: Sparen.de

dammit, never got a photo when i notched up 279 on the a92 past landshut.

anyway imvho, i have a spanking new turbo diesel japmobile and it rocks. of course it's not comparable with a badboy petrolhoover over 0-60 but that's fine with me as i'm past those days (well, that's a lie as i'm working on the wife to sort out something tasty as i now have la famille voiture).

anyway, costs less to run and unless you're planning on doing some serious alpine trials, go with a diesel. oh and if you get yourself a proper sound system, it sounds like, well, a mobile sound system. tractor? never hear it.

So sounds like for Netspeeds 20,000 per year mileage there is probably very little in it from a cost view. So he can get a petrol and avoid smelly diesel fill-ups, sounding like a taxi, wider choice of 2nd-hand cars, and probably better performance?

oh, and resale value, if that's a concern.

this one is very easy maths, JE.

assuming that the break-even is 15tkm, anything above that point benefist the diesel and comes directly from the lower fuel cost, higher efficency:

assuming 5.000km above the break-even (so yearly 20tkm):

for the diesel:

7 litres per 100km for 5000km with fuel costing 1,13 = total costs of 396 euros

for the petrol:

9,5 litres per 100km for 5000km with fuel costing 1,3 = total costs of 618 euros.

A diesel saves you 222 euros per year. (And i think these calcs are conservative and lean in favour petrol, since i didn't check current prices)

Depends on how your definition of "very little" is.

well apart from most of the arguments you raised being outdated (taxi sound, smelly etc) this one is not true in Germany. New sales of diesels are now higher than (I think, or at least approx. the same) as petrols. therefore second hand choice will be similar.

Best not to base your decision on factors that based on the UK market, where diesel sales are much lower and out-dated stereotypes.

I haven't owned a petrol engined car since I had Rover 623SLi in 1997. I will be going back to petrol briefly next summer but only because you can't get the Z4 with a diesel engine, lol. After that it will be back to my beloved diesels.

Fair call. Indeed to convert into a universally understood measure that would be a saving of 28.46 Oktoberfest Beers per annum.

Not true at all, I've been running a diesel for the last 8 months or so and I'd never go back. I drove a Audi A3 for a week and a Ford Mondeo for 4 weeks before I got my current car they were as quiet and as powerful as the petrol A4 I drove for 2,5 years. The diesel is by far cheaper to run.

Some diesels are a bit noisier than the Petrol equivalent (Mazda premecy for example) but that is unusual.

If you can get ahold of the latest ADAC issue they did a major comparison Diesel vs Petrol would be worth reading. Small cars break even is 4000k per year larger cars 12.000 per year.

Top Gear did a comparison VW Lupo Petrol 45mpg Diesel 75 mpg!!!

I think that says it all!

If your really serious rent a car for a week or two.

Personally I'd never go back to petrol.

Simple answer for me - if it's just an A-B type of motor and you're not an 'enthusiast' I'd take a Diesel, but if I was buying a car that I actually wanted to enjoy just for driving's sake, I'd go for a big capacity petrol engine (or one of those mad bastard VTEC engines - not a turbo, I don't like turbo charging - I'm a purist).

Insert photo of speedo here.

motorway cruising in a diesel engined car is a delight. Torgue for overtaking no pesky down-shifting, just put your foot down and feel it pick up.

But as Jimbo says, if you have money to burn and want a car to thrash about and have fun, then buy a... wait, you can also buy diesels in that class: BMW 535d. 3.0 litre diesel with two turbos, one small turbo for low revs, one large for high revs. Mo-Fo power, smooth release and a hell of a car to drive. Arguably as good as the M5.

Apart from the financial comparisons, it's a matter of personal taste. Diesel is simply not my cup of tea. Put it in a truck where it belongs, I say.

I mean, I drive a sports car – would you want a sports car that sounds like it's got a couple of loose screws circulating along with the pistons, stinks like a refuse chimney and has a black fart coming out of its rear end? No, ta.

Sounds like you lot only have experience of old diesels.

You can suck down the exhaust in a modern turbo diesel and it'll probably do you good (I jest), but seriously the days of loud smelly diesels are long gone.

@Oli2000
-Can I ask which car you have that will drive 270kph less than 5500rpm's? Seems almost impossible. My top is with a Mercedes S-Class doing 264 on the Croatian highway between Zagreb and Split and that topped out at 6500-7000rpm's.

it must be a diesel

@spuzzum
Toyota Supra, and it reaches top speed in overdrive, i.e. not at max rpm.

@Oli2000
Quite impressive. Will need to ride along with you one day or have a race. Speed sure is addictive given the right conditions. We should set up a first TT road race.

forget a road race, take your cars round the Nürburgring. Loads of fun to be had (especially the Nordkurve) without endangering the likes of Papa Gideon and family in his 1972 model Volvo Estate.

They're just not as good - I don't know why but diesels don't do it for me on an emotional level. Granted a BMW 330cd is a fabulous car (as is a 535d), but I'd still much rather have a big petrol engine...personal preference entirely, but I'm a petrolhead - not a dieselhead (though as a couple Foxy and I only have one car at the moment...and it's a diesel). Believe me, though, once I've got the little issue of a house sorted out and I do buy a car it'll be a small, lightweight, petrol engined motor - quite likely an Elise.

That, by the way, is the other problem with diesels - they're a fair bit heavier, and so in a fwd front engine layout they tend to understeer more than their petrol brethren and as any keen driver will tell you, understeer is rubbish - oversteer is where it's at - purely for shits and giggles.


Probably the worst idea posted on TTM ever - and believe me, when the liberals on this site see that suggestion, you're in big trouble - run and hide now!!!

Yeah, but what about the TTers that own a diesel? We'd have to exclude those... no wait - they can have a tug-of-war competition instead

probably the most irreverent idea posted on TTM anyway and made me chuckle. but you will get nailed by the tofu-loving guardianistas.

anyone tried the rx8 by the way? would seriously like one after trying it out when i bought my mazda 6 diesel towing wagon.

any keen driver wouldn't touch a front wheel drive car!

You know how I like to disagree with you Owain, and I'm disagreeing again now - the Integra Type R is a fabulous bit of kit - and it's fwd. Though I grant you, by and large, rwd is the way forward.

As for RX-8s - meh! - get a Nissan 350Z instead. What a weapon that car is. Hired one for a weekend and loved every second of it.

Turbos are a real pain, Turbo lag scares the shit out of you when your trying to cut into traffic from a dead stop and hit the gas and nothing happens!

or, when on a wet roundabout, the turbo suddenly spools up and spits you into the bushes backwards.

BMW 535d has no turbo lag. It was two turbos, one with a smaller intake that can build up pressure quickly at lower revs and a mo-fo larger one that kicks ib higher up the scale and allowes more top end speed.

From what I understand if you wanna an early visit from the grim reaper you buy an old 911 turbo?

Inserts picture of speedo:

Rear engined (way out behind the rear axle), rear wheel drive, turbo lag so bad the turbo sends a post card to warn you of its arrival, and a wet corner...yep, you're gonna die.
[img]http://hulk.osd.wednet.edu/~lewisnt/nato/speedo.jpg[/img]

I had an A4 petrol turbo and it was bad for turbo lag particularly when coupled with an automatic.

I stand slightly corrected, some diesels are a touch noisier than others, but its nice that it warns cyclists that you coming and they generally move over.

It's not the noisiness (i.e. loudness) that's the problem – it's the actual sound the thing makes. While a diesel engine in a larger truck sounds ok b/c it's got enough volume to make it sound like a decent, heavy working machine, the tiny diesels in smaller cars simply sound terrible, often accompanied by a whining from what sounds like an overloaded turbo, i.e. they sound like a terrible effort is needed to make the poor thing move. Perhaps a matter of taste, but to me those cars do not sound technically aesthetic, i.e. not the way to go.

Weeeeeeell, I'm definitely an NA man myself, but I also love that sudden surge of power in the older turbos, great fun. The new ones are hardly noticeable, kinda like hitiing the sweetspot with the VTECs.

True, and I suppose there's something to be said for Supercharging and Turbocharging (or as in the new Golf 1.4 super charging AND turbo charging at the same time). However, as Drivin' West was always fond of saying - there's no replacement for displacement and when I finally got to go for a proper thrash in a 3.5 litre car I totally understood what he meant.

That's a true American saying that one, but how untrue it is...there definitely is a replacement for displacement, I cheekily call it "technology". Think M3, M5, Skyline GTR, WRX & Evo's.

As the germans say "Hubraum ist durch nichts zu ersetzen, ausser duürch mehr Hubraum". (Nothing replaces displacement, except more displacement)

Quiet well behaved cars are all well and good but I once sat in a cousins Ford Mustang and when the engine was running by god you knew it.

All very irresponsible from a environmental point of view of course but hey if you don't use it it's going to clog up some poor seabird.

Read a nice little article about the "Batmobile" car they used in the latest film.

Basically they made a full-sized Batmobile because when you use any scale size models it is impossible to gain the realism. They always look wrong.

The reason is down to the relationship between weight/size and volume (I am sure the physics tekkies can explain in more detail from the other thread).

So even if you make a 1/4 scale model, it actually weighs only 1/12th as much as the real thing, and so "bounces" too lightly over obstacles etc.

The point of the article was that no matter how big and powerful an engine you chuck in a car (Porsche Cayenne Turbo or whatever), if it is too heavy, it can never replicate the feel of driving for instance a Lotus Elise.

That's because in the Lotus Elise they just throw the car over the engine and hope it stays on.

Well in the last 20 years Mustangs have turned into a caricature of what they used to be. The essence though has stayed, as it has for most US cars: large, inefficient clumsy/primitive automotive technology, which is why their market is flooded with European/Japanese cars and you rarely see a US car over here.


Disagree. Nothing replaces displacement, except… a turbo!

How about a Nitrous Oxide scooter? Good power to weight ratio.

both Superchargers and Turbo have there advantages and disadvantages. Obviously Turbo's biggest disadvantage is its lag, the time it take to 'spool up', Supercharger doesnt have this problem as it can produce the boost at low rev's per minute.

turbocharger is cheaper to run / more econimical as it makes use of gasses that would be otherwise lost out of the exhaust, the supercharger i think it connected to the crank and this requires more fuel to run.

turbo can damage the drivetrain if the surge is too powerful

Turbo is quieter than a supercharger and can in some cases make your car quieter that it would be non-turbo'd.

Max Power output of the turbo will always be greater than a supercharger although more difficult to tune.

Ran out of shit to say now so i'll shut up

What freaks me about turbos is that they run up to 180,000 rpm. Yes you read correctly. 180,000 spins a freakin minute. No wonder they get a bit warmish.