Why do we still have petrol cars?

jayok

If modern day diesels are more fuel efficient, produce more torque and sufficient amounts of power, why do we still have the petrol car?

Excluding the specialists "sports" cars such as RX8's or M3's and so on, the average punter just needs an A-to-B car and they really don't care about the engine why don't we see 90% diesel sales and say 10% petrol (for the specialists)?

I know on the continent that diesels outsell petrol cars something like 2:1, but then again, why do petrol cars even sell?

Exluding performance, what would someone buy a new petrol car instead of a new diesel?

Wishbone Ash

For those doing low milage, the initial extra cost of most diesels probably wouldn't balance out.

peasant

One reason would be that a petrol engine is cheaper to make and lighter (because of the lower compression rate). It als o has longer service intervals.

Especially in smaller cars (compare a 1 liter petrol to a 1.3 liter diesel) you'd have to do a lot of driving before your lower fuel consumption pays you back for the higher purchase price and maintenance cost of the diesel. (more so now, that diesel is the same price or more expensive than petrol)

craichoe

peasant wrote: »

One reason would be that a petrol engine is cheaper to make and lighter (because of the lower compression rate). It als o has longer service intervals.

Especially in smaller cars (compare a 1 liter petrol to a 1.3 liter diesel) you'd have to do a lot of driving before your lower fuel consumption pays you back for the higher purchase price and maintenance cost of the diesel. (more so now, that diesel is the same price or more expensive than petrol)

Diesel is well cheaper than petrol on the continent though !

Also, i thought service intervals on the new diesel engines was the same as petrol ?

cantdecide

Prohibitive purchase price- you have to be doing high mileage just to break even.

The next few years will see a lot more diesels after the July changes, though.

cantdecide

...oh and refinement. Diesels are still only getting there, especially the 4 pots. My dad recently sold his GS300- it was remarkably quiet and refined. It will be another few years:rolleyes:before you will be able to stand next to a running diesel and not hear it idling!!

Niall1234

If everyone switched to Diesel then the price of Petrol would go down.

It all follows the laws of Demand and Supply. If people perceive that a Diesel car would be cheaper, then they will go for one.

If everyone went with Diesel, price of Petrol would fall, everyone would then buy Petrol and the prices would balance off again.

cantdecide

As it stands, diesel is WWWAAAAAYYYYYY overpriced consiering how much cheaper it is to produce, but I'm sure everyone knows that.

JHMEG

Be thankful that more people are *not* using diesel.. there'd be more lung cancer, asthma, respiratory problems etc, especially in children. I can't find the source at moment, but it's estimated that 8,000 people a year die in the UK due to illnesses caused by diesel fumes.

They've only recently found out how to tell lung cancer caused by diesel fumes from lung cancer caused by smoking, so expect in the come years actual hard numbers on the amount of people killed each year by diesel.

Ironically enough diesel emissions are set for a major clean up with euro 5 in 2011, but still won't be as clean as petrol.

E92

Some people prefer the way petrol engines drive for a start. Some people prefer the fact that petrols are still quieter. They're still much cheaper to buy(though not for long).

People who aren't into cars still think diesels are as slow as walking, and extremely noisy, so they're definitely not even going to consider diesel(though they might come July).

The Euro 6 standards for diesels are the same as those for Euro4 petrols(excluding Carbon Monoxide, the limit of which is half for diesels).

A lot of the new Euro 5 and Euro 6 diesels will need AdBule, so as to pass the test standards. You're gonna have to pay for that every time you get the car serviced, and for the cost of these advanced emissions systems.

At the end of the day, because petrol is taxed so much higher in the Continent, it is much cheaper to run diesel cars. The marketing people in BMW or any of the other makes selling diesels in the US are always keen to tell US drivers how many people in Europe drive diesel powered versions in their car's ranges, because diesels are so much quicker in the real world than petrols, and almost as quiet and of course they are more economical.

What they never tell the US customers is that Europeans love diesel because it's so much cheaper, a lot of Governments, including our own from July help subsidise the cost of buying diesel.

Don't get me wrong, I don't hate diesel, some of the fastest car drives I've gone in were in diesel powered taxis, so I know they are very good performers, I have told anyone who's asked here about buying new cars to wait and get the diesel models, if I hated diesels I'd be saying buy now and don't bother with diesel, the 30% greater efficiency in terms of fuel consumption can't be ignored either, but a bit of reality wouldn't go astray either;)!

boomboombazza

isn't diesel worse for the environment?as if that would bother me...im a grade a gass guzzler (3.0 M3)

JHMEG

E92 wrote: »

because diesels are so much quicker in the real world than petrols,

Oh god no, not this myth again. In the real world cars have gears, which diesel fanboys seem to conveniently forget to factor in.

In the real world petrol is king of speed.

JHMEG

boomboombazza wrote: »

isn't diesel worse for the environment?as if that would bother me...im a grade a gass guzzler (3.0 M3)

Petrol is worse for the planet than diesel. Diesel is worse for people than petrol.

Green Hornet

jayok wrote: »

If modern day diesels are more fuel efficient, produce more torque and sufficient amounts of power, why do we still have the petrol car?

Excluding the specialists "sports" cars such as RX8's or M3's and so on, the average punter just needs an A-to-B car and they really don't care about the engine why don't we see 90% diesel sales and say 10% petrol (for the specialists)?

I know on the continent that diesels outsell petrol cars something like 2:1, but then again, why do petrol cars even sell?

Exluding performance, what would someone buy a new petrol car instead of a new diesel?

I guess your last statement is the reason that many people buy petrol cars.

It's the performance and lower purchase cost.

Many 1.8 L petrol cars will now routinely give 40 mpg on reasonably long journeys and are much more refined. No matter what nonsense you hear from diesel heads a 1.8 petrol will almost always outperform a 2.0 turbo diesel.

The_Conductor

Niall1234 wrote: »

If everyone switched to Diesel then the price of Petrol would go down.

It all follows the laws of Demand and Supply. If people perceive that a Diesel car would be cheaper, then they will go for one.

If everyone went with Diesel, price of Petrol would fall, everyone would then buy Petrol and the prices would balance off again.

If there was a perfectly competitive market this might happen. There isn't. Over 80% of the price of the fuel at the pump is taxes and duty- which will remain constant regardless of demand. The production cost of diesel, as a heavy oil, is significantly less than the production cost of petrol. As more refining capacity was freed up to produce the much less refined diesel, the production cost for diesel might fall even further, and that of petrol rise. So- its quite possible that the inverse of what you are suggesting may in actual fact occur.

jayok

JHMEG wrote: »

Be thankful that more people are *not* using diesel.. there'd be more lung cancer, asthma, respiratory problems etc, especially in children. I can't find the source at moment, but it's estimated that 8,000 people a year die in the UK due to illnesses caused by diesel fumes

While I didn't know this and can't refute this, wouldn't trucks, buses, trains, ferries, etc, emit far more diesel fumes than cars (on a mileage basis). As such wouldn't these vehicles be the main culprits?

Green Hornet wrote:

Many 1.8 L petrol cars will now routinely give 40 mpg on reasonably long journeys and are much more refined. No matter what nonsense you hear from diesel heads a 1.8 petrol will almost always outperform a 2.0 turbo diesel.

Really? The reason, I asked about the original post, is we currently have a 2 litre CR-V (with that DOHC i-VTEC thingy) and I've been driving a 1.8 TDCi Ford S-Max. I have to say, from a torque delivery, power, economy and refinement, the S-Max is winning. Not that the CR-V is a unrefined or anything, but I rarely get over 31mpg with the CR-V and I'm getting 45+ with the S-Max. So in this instance, I don't see how the 2 litre petrol is better than even a 1.8 Diesel.

<EDIT> I should add I drove the 2 litre petrol S-Max, but after the diesel this didn't even raise a gallop in the above terms.

John R

smccarrick wrote: »

If there was a perfectly competitive market this might happen. There isn't. Over 80% of the price of the fuel at the pump is taxes and duty- which will remain constant regardless of demand. The production cost of diesel, as a heavy oil, is significantly less than the production cost of petrol. As more refining capacity was freed up to produce the much less refined diesel, the production cost for diesel might fall even further, and that of petrol rise. So- its quite possible that the inverse of what you are suggesting may in actual fact occur.

The production cost has little to do with the pre-tax price of fuel, it is all about supply/demand. The huge increases in oil prices has been because demand is increasing not because production costs have shot up.

JHMEG

jayok wrote: »

While I didn't know this and can't refute this, wouldn't trucks, buses, trains, ferries, etc, emit far more diesel fumes than cars (on a mileage basis). As such wouldn't these vehicles be the main culprits?

In most Irish cities and town centres you won't find ferries or trains... as well as cars you'll only get trucks and maybe the odd bus.

From the EPA 2006 report on air quality in Ireland:
"The main pollutants recorded in 2006 were nitrogen dioxide and particulate matter (PM10)."
"NOx includes the two pollutants nitric oxide (NO) and nitrogen dioxide (NO2). Power-generation plants and motor vehicles are the principal sources of NOx,"
[Diesel engines can produce 24 times more NOx than petrol. (source)]
"The main sources of PM10 are the combustion of solid fuels and road traffic, in particular emissions from diesel engines."

As E92 pointed out, Euro 6 emissions regulations, which aren't due till 2014, will clean up diesel emissions to the standard that petrol is at today (euro 4).

If you care about your health and your kids' health, think twice about diesel.

The_Conductor

John R wrote:

The production cost has little to do with the pre-tax price of fuel, it is all about supply/demand. The huge increases in oil prices has been because demand is increasing not because production costs have shot up.

Not entirely true. My argument was that a greater demand for diesel would not result in a surplus of petrol, and a consequent reduction in its price. Vis production costs, as a much less refined product, with a much higher crude recovery ratio- the production cost of diesel has a lower PCR, at about .4, than petrol which is 1.2 -Its far more economic to produce the diesel, and to up its production in lieu of petrol production if the demand shifts in that direction (totally aside from the tax/duty reasons which are artificially reducing the price elasticity of demand in the first place). To believe that petrol prices will fall as a result of lower demand in favour of higher demand for diesel is living in a fantasy world.

Green Hornet

jayok wrote: »

Really? The reason, I asked about the original post, is we currently have a 2 litre CR-V (with that DOHC i-VTEC thingy) and I've been driving a 1.8 TDCi Ford S-Max. I have to say, from a torque delivery, power, economy and refinement, the S-Max is winning. Not that the CR-V is a unrefined or anything, but I rarely get over 31mpg with the CR-V and I'm getting 45+ with the S-Max. So in this instance, I don't see how the 2 litre petrol is better than even a 1.8 Diesel.

<EDIT> I should add I drove the 2 litre petrol S-Max, but after the diesel this didn't even raise a gallop in the above terms.

In fairness, the CRV is a bigger, heavier set of wheels than the S-Max. I guess I'm referring to the smaller saloon, hatchback bracket. I drive a Civic 1.8 iVTec saloon and routinely achieve 40+ mpg on a daily 80 mile round trip.

bazz26

jayok wrote: »

If modern day diesels are more fuel efficient, produce more torque and sufficient amounts of power, why do we still have the petrol car?

Excluding the specialists "sports" cars such as RX8's or M3's and so on, the average punter just needs an A-to-B car and they really don't care about the engine why don't we see 90% diesel sales and say 10% petrol (for the specialists)?

I know on the continent that diesels outsell petrol cars something like 2:1, but then again, why do petrol cars even sell?

Exluding performance, what would someone buy a new petrol car instead of a new diesel?

Alot of it can be personal choice.

E92

Another thing is that every litre of diesel burned produces 13% more CO2 than every litre of petrol. So a petrol doing 50 mpg produces the same CO2 as a diesel that does 56.5 mpg.

Based on that, diesel should cost 13% more at the pumps than petrol, if we're serious about cleaning up our act, plus the health risk as outlined by JHMEG has yet to be mentioned in any discussion about the new VRT system.

We seem to have buried it under the carpet as far as I'm concerned.

Now modern diesels are infinitely cleaner than diesels from even 10 years ago, and the gap between diesel and petrol is way, way smaller than it used to be in terms of pollutants etc., but petrol is still well ahead.

Any diesel that meets the Tier 2 Bin 5 standard in the US is unquestionably greener than a comparable petrol though.

The US emission standards are fuel neutral, therefore even though even though every unit of diesel is a greater polluter of CO2 than each same unit of petrol, the decrease in fuel consumption which is an inherent characteristic of diesel is more than the increase in CO2 per unit of fuel burned (i.e. a reduction of 20-30% of fuel used is clearly more than an increase of 13% of CO2 per unit of fuel burned), this of course should happen here with the European Emissions standards, but sadly doesn't.

Audi did win LeMans twice in a row with a diesel car, but they also got the rules changed so that they would be biased towards diesels, which is why they entered a diesel for it in the first place.

Some of their road going petrol cars still have more bhp per litre than the R10 TDI but unlike the R10, these cars are designed to last 200k miles, whereas the R10's engine only had to last 24 hours. I mean the Audi S3 and the new TT-S all have more bhp per litre than the R10 TDI(the R10 has 118 bhp per litre, the S3 has 132.5 bhp per litre(265/2), the TT-S has 140 bhp per litre (280 bhp from it's 2.0 engine, an extreme example I admit, but nevertheless we are talking about cars that are supposed to go fast.

Although many road cars nowadays offer a higher bhp per litre from diesel cars than from petrols, that's largely because all diesels have a turbo these days, many have 2 turbos, while the vast majority of petrols still have no turbo, and with the exception of BMW, FSI/TSI/TFSI VAG, and Honda and a handful of other engines, petrol engines in most cars are technologically speaking stone age compared to diesel engines, and naturally this exaggerates the torque and economy advantages of diesels, as well as in some cases giving them even more power than similar size petrol engines too.

I mean we can all marvel about the new twin sequential turbo 2.0 litre diesel engine from BMW, what with 102 bhp per litre, and that is a very high amount even for a petrol engine. But the M3's engine has 105 bhp per litre, and not 1 turbo never mind two sequential ones in sight, so petrol still clearly has the capability of providing loads more power than diesel, it's just that nobody seems to try these days.

After all the Nissan Skylines 2.6 litre engine is known to be able to give a 1000 bhp, now thats no less than 384 bhp per litre, FWIW if we made it a 5.5 litre, with that sort of a specific output, a 5.5 litre version would give an incredible 2,115 bhp, compared to the Audi R10's 650 bhp, 2,115 bhp clearly blows 650 bhp into the weeds.

alias no.9

Green Hornet wrote: »

In fairness, the CRV is a bigger, heavier set of wheels than the S-Max.

In fairness, it's not. The S-max is longer, wider and heavier than the CR-V. The CR-V is taller due to the raised ride height, being a soft roader and all that.

JHMEG

E92 wrote: »

But the M3's engine has 105 bhp per litre, and not 1 turbo never mind two sequential ones in sight.

11 year old F20C from the S2000: 120bhp per litre. Normally aspirated. Makes the M3's engine look like an under achiever.:D;)

SV

Well to be honest..I just like not sounding like a tractor as I go around.

-Chris-

E92 wrote: »

Another thing is that every litre of diesel burned produces 13% more CO2 than every litre of petrol...

...After all the Nissan Skylines 2.6 litre engine is known to be able to give a 1000 bhp, now thats no less than 384 bhp per litre, FWIW if we made it a 5.5 litre, with that sort of a specific output, a 5.5 litre version would give an incredible 2,115 bhp, compared to the Audi R10's 650 bhp, 2,115 bhp clearly blows 650 bhp into the weeds.

E92, I don't know you, know about you, know what you do or even know what age you are but I think the members of the Motors forum owe you a ebt of gratitude for the info you give and the time you put into it.

Nice one!

E92

JHMEG wrote: »

11 year old F20C from the S2000: 120bhp per litre. Normally aspirated. Makes the M3's engine look like an under achiever.:D;)

Yup, though the newer i-VTEC engines have a lower specific output than this(the JDM Civic and Integra DC5 Type-R spring to mind here), what have Honda been up to ever since:D?

Nobody can deny that the S2000's ability to rev to 9,000 rpm and produce 118.5 bhp per litre without any form of forced induction is quite a staggering achievement in reality.

(in fairness the S65B40 revs to 8350 rpm which is nevertheless amazing for a V8, though the Honda even has a higher torque per litre than the S65B40 too, that said it comes much higher up in the rev range than the M3s the S2ks torque comes at 7500 rpm compared to the M3s peak torque at a much lower 3900 rpm, I put this in brackets because I know how much you love torque:p)

Though I note from Wikipedia that a JDM S2000 will give you 125 bhp per litre from the same F20C engine, amazing stuff really.

E92

AudiChris wrote: »

E92, I don't know you, know about you, know what you do or even know what age you are but I think the members of the Motors forum owe you a ebt of gratitude for the info you give and the time you put into it.

Nice one!

In fairness a lot of people know far more about cars than I do here, though yes I'm completely nuts about them alright:D!(though I do like loads of other stuff such as surfing, which absolutely rules, but cars are clearly my favourite, I'm going for a spin in an S5 any day soon, I'm like a dog with a new bone at the thought of it:p)

I knew very little about cars before I joined boards compared to what I know now, basicallly if I see read or hear something new and it is of interest to me and anything to do with cars certainly is of interest to me, I'll remember it, so a lot of things I know about them now are often things said by other people here already, and I've remembered it(the emissions stuff was mentioned by JHMEG a good few months ago for exaple, and I still remember most of what he said;))! If it's something uninteresting, then I'll have forgotten it a fewseconds after I heard it though:D. Which is one of the great things about cars, there's always something new to know about them, and the whole engines and all that stuff keeps changing all the time, so it is absolutely fascinating really.

And I certainly know SFA about the goings on under the bonnet, the height of my mechanical skillis are my ability to change lightbulbs and to use a dipstick, and I know what all the lights on a dashboard mean too, as well as some of the funny sounds from a car e.g. I know what a tappety engine sounds like, but that's it.

So I guess what I should say thanks to the other boardsies for sharing your knowledge really:p.

Robbo

E92 wrote: »

After all the Nissan Skylines 2.6 litre engine is known to be able to give a 1000 bhp, now thats no less than 384 bhp per litre, FWIW if we made it a 5.5 litre, with that sort of a specific output, a 5.5 litre version would give an incredible 2,115 bhp, compared to the Audi R10's 650 bhp, 2,115 bhp clearly blows 650 bhp into the weeds.

The Audi R10 engine has to contend with an air restrictor (as all Le Mans cars do) which effectively limits it to ~550 bhp. Where it comes into it's own is that sheer amount of torque it produces (enough so that the R10 has a 5 speed box instead of a 6 speed one in the R8 and the ECU cuts the torque in the lower gears to save the rear tyres) and the ability to go longer between pitstops. As a consequence, there's been much bickering about equivalency formulas for Le Mans.

It is quite foolish to extrapolate in a straight line when you're talking about engine output. It simply doesn't work like that. There's cooling issues, driveability, anti-lag and a whole host of other problems.

Matt Simis

JHMEG wrote: »

Oh god no, not this myth again. In the real world cars have gears, which diesel fanboys seem to conveniently forget to factor in.

In the real world petrol is king of speed.

I think you should lay off generalising so much. Most of diesels are wheesy, underpowered, A-B cheapo wagons. That doesnt mean diesel as a technology is slower or faster than "petrol". You dont need hyperbole to argue with these "diesel fanboys" as they have to be outnumbered 10 to 1.

And your pollutant info, while I believe is correct, is being portrayed in a very lobsided manner; we have one fuel that leads to skins cancer and global warming and another that leads to lung cancer and respitory problems... erm pick one?

They both suck regarding "eco" concerns and they both need to be replaced, so whats the point berating one over the other?

Biro

E92 wrote: »

Yup, though the newer i-VTEC engines have a lower specific output than this(the JDM Civic and Integra DC5 Type-R spring to mind here), what have Honda been up to ever since:D?

Nobody can deny that the S2000's ability to rev to 9,000 rpm and produce 118.5 bhp per litre without any form of forced induction is quite a staggering achievement in reality.

Not to mention the even more remarkable fact that it's one of the (if not the) most reliable engine in the world!