Say, what's the difference between a diesel and a petrol car anyway?

Petrol is generally quieter

EPM wrote: »

2nd gear, 1500 revs...wait for it...2000 revs...still waiting...2500 revs wheelspin:mad:

Stupid diesels:pac:

Maybe on some VAG diesels but not all diesels.

Waylon Weak Ration wrote: »

I don't know anything about cars, at all, and I've been struggling to find answers to the following questions online:

"In layman's terms, what is the difference between a diesel engine and a petrol engine

Thanks for reading.

the main difference between the engines is the fuel ignition, petrol engines use
an electric spark to ignite a highly refined fuel at relativley low compression

where as diesel engines use heat created by very high compression to ignite
a less refined fuel oil.

Onkle wrote: »

And you Tdiddly VAG heads slag off us VTEC YO drivers

Turbo diesels is like VTEC minus the fun and with the Rev range in Reverse.
Not that fast to just under 2000rpm, then 90% of the engine torque "happens" and is effectively over by 3500rpm. Yes our current diesel will rev to over 5000, but there is little benefit (and FWIW the common VAG diesels arent that great in anything but economies of scale).

The longer you hold down the pedal in a diesel the more "diminished" the power available is. The longer you hold down the pedal in a petrol, the higher the revs climbs and the faster you go.

The diesel has a narrow powerband, the annoyance of "driving on" a diesel is the fact you have to shift gears continiously to keep it in 2000-3000 rpm. I remember the "old" arguments we used to have on Boards where people said diesels dont need to shift as much as petrol. Complete BS, diesels need to shift far far more than a petrol. Both types of Combustion engines have gear boxes for exactly the same reason, however the power band size determines the amount of shifting to keep in the sweet spot. Diesels have a small powerband.

Now if you have a 6speed (or 7/8speed in latest diesels) Automatic box with fast shift times, it can make a huge difference to the drivability of a diesel. I think something like the new BMW F10 535d with the 8speed gearbox would "feel" like it has mountains of smooth power.

I don't think people realise how much expensive trouble modern high pressure diesels are giving in the real world.

Modern diesels inject at up to 18000 psi with dire consequences when things go wrong
Examples

Avensis injectors € 4k



Renault injector pumps if you put petrol in ???? 2-3 K

TDCI fords faulty injectors burn holes in pistons 4.6K for a short block.

Passat diesels Computer troubles and particulate filters

Lexus 220d burning oil 7K

BMW diesels suck in swirl flaps new engine 7k

Along with dmf, egr, and now particulate filter problems !!!!!!!!!!!!

Skoda & Hyundai dual mass flywheels € 2.5 K

Also on all brands any misfire usually results in bills for thousand rather than hundreds.

A few quid extra on petrol every week can be a huge saving in the long run

To OP: diesel engines can burn agri-fuel.... petrol ones can't..... sorry only joking. Honest.

I think wikipedia can explain a lot more than you'll get from this thread tbh.


http://en.wikipedia.org/wiki/Diesel_engine

http://en.wikipedia.org/wiki/Petrol_engine

Kaiser2000 wrote: »

You left out the now infamous "injector failures" on early 2.0 TDI (05-07/8 era) Passats, €1k a piece and generally the rest seem to fail not long after the first.


I DID have to replace the DMF though before Xmas (another €1000), but since then it's been running fine! (serviced on time and at a main dealer )

My whole point another €1000


I left out loads of car problems that I don't have concrete info on for fear of being lynched here.

I never mentioned turbo problems which is universal on all brand Diesels

gyppo wrote: »

I think driving styles have a lot to do with this too. Many diesels suit lazy drivers (like me) who are happy to let the low down torque of the oil burner pull it around at 1500rpm or so, rather than changing down gears in a petrol engined version.

True, if you get where you are going without having to change gear, then yeah its good enough. However to change gear at the same pace as a turbo petrol or large CC petrol in a (not slow 200bhp) diesel I need to maybe make 3 gear changes in the diesel vs 1 in the petrol. Its the opposite of "lazy" IMO.

Our Alfa 156 2.4JTD has almost as much torque (300ft/lbs) vs my Audi S8 4.2 V8 (317ft/lbs @ 3400rpm) in a car 400kg lighter yet to overtake at the pace of the Audi.. well its not possible, but to get close to it you need to do some "race" style fast shifting in the Alfa.

Bigus wrote: »

I don't think people realise how much expensive trouble modern high pressure diesels are giving in the real world.

Modern diesels inject at up to 18000 psi with dire consequences when things go wrong
Examples

Avensis injectors € 4k



Renault injector pumps if you put petrol in ???? 2-3 K

TDCI fords faulty injectors burn holes in pistons 4.6K for a short block.

Passat diesels Computer troubles and particulate filters

Lexus 220d burning oil 7K

BMW diesels suck in swirl flaps new engine 7k

Along with dmf, egr, and now particulate filter problems !!!!!!!!!!!!

Skoda & Hyundai dual mass flywheels € 2.5 K

Also on all brands any misfire usually results in bills for thousand rather than hundreds.

A few quid extra on petrol every week can be a huge saving in the long run

Don't forget that all PSA 1.6 HDis are not the best with the old DPF either, and also the VAG 2.0 TDI PD can have a defective oil pump which sprays oil all over the engine and results in the engine being a write off!

I agree with you, I'll gladly pay the extra few quid in fuel in the knowledge that the worst I'll get is coil pack or MAF failure and if I'm extremely unlucky I'll get HG failure too.

That said, VW 1.4 TSIs have this habit of lunching their supercharger (and the NA 1.4 is appalling for reliability) and BMWs with Efficient Dynamics have this habit of going through injectors at a rate of knots, so petrol isn't always better

EPM wrote: »

Not as sudden as the PD

The who with the what now??