towing with petrol or diesel

[Lutz]

Neither maximum torque nor maximum horsepower alone determine a car's towing ability. It is a combination of the two. After all, horsepower is basically torque x speed, so a low torque can be offset by a corresponding higher engine speed. It's just that a very 'peaky' power curve makes for unrelaxed driving as it requires frequent gear changes. To assess towing performance it is therefore important to know at which engine speeds the respective maximum values occur - or, better still, to have a look at the complete torque and power curves.

 

[Zafiral]

I feel that the diesel engine's market leading cost saving is now questionable at best.

I used to have a Civic 2.2 CTDi and compared to the 1.8 iVTEC of the same car, the cost savings were at best limited.

The mpg savings between my own car (the CTDi and the petrol service loan cars I had were only 15 - 16% (50 mpg diesel - 42 mpg petrol). As diesel around by me is 98.9p compared to petrol at 88.9p erodes the vast majority of the saving. The diesel service was

 

[g_374369443]

Dustydog.

DMFs are not solely used on turbo diesel engines, they are common on petrol engines too.

They are their to add further cushion to the drive train and make things easier. But again because of the huge torque that turbo diesels develop from so low down in the rev range, they take more of a hammering from them, than they do in the petrol engines. Although it doesn't mean petrol cars won't have wear issues, after all they are a wear item.

Euro. Glad to hear your BMs gave no trouble,in your experience. I have no experience on them, but again I take the word of those on forums to do with these issues, be they BMWs own owner sites or diesel related ones, or industry news journals.

Which I am sure you agree, has a far greater spectrum for exactly what is what,and how common a problem can occur!

Indeed it has lead to a huge after market of specially designed, single plate flywheels/ clutch replacements from companies such as Sachs, or indeed companies like GM, also offering the alternative.. http://www9.qha.com/shared/pdf/PR199-08%20QH%20Launches%20DMF%20replacement.pdf

 

[seth1]

With out starting another major upset,in my opinion i feel ive not infringed anyone ,or made anythink personal but infact its been the otherway round,im merely pointing out the correct facts,not something ive just read in my dinnerhour.But according to G ive been left behind.Pehaps the last 25 years as a diesel engineer,and company owner, who has business abroad,is an authorised American engine distributer,has strong links with a German industrial engine maker has been a waste of time.The latest

 

[xtrailman]

Wellcome back Seth

 

[seth1]

Just read the remaining posts above my last one.I do admit there is odd problems with bosch EDC 15 C7(common rail),nozzles sticking open,bad hp pumps,this is the same system fitted to most cars,although yes ours is on big stuff.This is generation 2 common rail 1650 bar as oposed to gen 3 1800bar.From what we,ve seen and according to Munich,down to water ingress or filters changed wrong.

G please dont insult my intellegance,by making the assumpion i liken unit injection as used by Cummins PT,Daf upec,Caterpillar,Volvo,Scania,VW pd to common rail as,as you know the injector actuation is totally different as are the injection pressures.According to you most trucks use common rail,do you mean MAN,and Iveco ,all two of them.

Truck engines use all the rev range to elimate soot!Imagine the implication on fuel economy of that statement,that must be why Cummins introduced electronic engines over 20 years ago,with max torque at 1350rpm,Liebhere/MAN have just released their new joint development D28,v8 max torque at 1300rpm and guesswhat,two vgt turbos.all that soot.Max engine speed of both is 2100rpm.

Cylinder temps on average 600 degrees c and we have vapour from an exhaust port destroying a turbo.

As said a little bit of knowledge is dangerous.But as normal above is factual as seen every one of my working days.

regards seth

 

[g_374369443]

I would say welcome back Seth, but i did not know you had left,but good to see you posting.

Have decided to take your advice, and have indeed started emailing,all sites that, contrary to what the majority of the professional garage trade believe.They are all wrong, and the known problems concerning cars and egr valves and turbo's and soot ect ect, are all wrong,Well i would but you are quick to come in with the "don't insult me mentality"When you are actually doing the insulting by not checking the facts! It seems if its not something you have come across whilst working on lorries!It doesn't exists!

{And this is not insulting mods}but seth Do you actually understand turbo's Yes that might sound crass but your statement concerning the fitments of two turbos,and max power at 2100rpm or whatever, means what? Well it looks like an a temp to say"look thats really low rpm, so if G knew what he was talking about concerning soot, then this low rpm,would make soot a problem.And its not"

Trouble is seth, You seem to miss the point that at 2100rpm these turbo's fitted to these lorries have gone through their full circle!, unlike a car thats only at 2100rpm, which is only at half revs.I am sure you can tell me loads about injectors and injector pumps, but Id leave it there, you have not answered anything i have asked, and you seem to think everything revolves solely around the injection system! Which it clearly does not in the 21st century!

 

[seth1]

G,you seem to emphasise truck engines all the time,are these engines not at all the same as for other applications,the German unit i was refering to is fitted industrially.Problem is G everything you mention in detail is incorrect,you refere to CR but no nothing about it,and it shows in your desciption of its operation.What you claim doesnt make sence,put 2and 2 together,what goes for 1 goes for the other.

But now i dont understand how turbocharging works,what we talking about?both types of VGT,wastegate or non wastegate,boostpressure,were boost pressure comes from?What?

 

[seth1]

forgot to say G,your understanding is so great ,why not grasp the posting ,forget max engine speed at 2100rpm,when max torque comes in at 1300rpm,THEY ARE NOT DESIGHNED TO BE RAN AT THE UPPER END OF THE RANGE,ITS BAD ON FUEL,ITS NOW CALLED A FLAT TORQUE CURVE.THE WHOLE POINT OF ELECTRONIC ENGINES AND VGT TURBOS.It also contradics what you type," as lorries use all their rev range".They do not.Happy caravaning

seth

 

[g_374369443]

this started off, as a what is best opinion! I stated that it wasn't that simple anymore, and it is not.

You seth then decided it was!, although, only using your own limited workshop for your opinions!And indeed giving your expertise to some users, that proved incorrect! ie, told someone his dealer didn't know what they were talking about,but funny enough they somehow fixed the problem, that you were sure was injector system related!which it was not!

I told you the why's and wheres to look, in other words the data i was giving was collected from, 10s of thousands of individuals professional and semi professionals.So clearly given the choice of believing vast data or believing someone who still thinks 4500rpm is the max a diesel engine can rev to,i know where the better data comes from.

Now you can stick your chest out all you want, the fact is you really should spend a little more time checking whats new and what needs to be looked out for, cuzz, the fact you not herd of or come across any issues concerning soot build up,and problems arousing from it only high mileage cars,Means you have very little to offer of advice on the modern car!

Indeed your turbo response is so funny, hands up all truckers who only use half the rev range thats available to them?

Now this is fundamentally why the diesel car engine gets a build up of soot through its entire system! And you still cannot fathom why!So there is no point me re telling you, it past you by the first time so it will again.

So to anyone running a 4 or 5 plus year old modern diesel, that had a mixed life and done a few miles, look into the inlet tracked just after the EGR valve..Seth says it wont be a disgusting site, every expert will tell you different!

And why not try your local turbo re builder!,ask them if they do services? ask them if they come across Sticky VNT vaines? Again Seth laughs, but ask the experts, it seems they know different.

So seth stick to injectors or reading technical data, that really means nothing.

Me,i have a problem, the bus is running 18 psi boost at 2000rpm [as it should] but at 3500rpm [where it should run 16 psi, its only running at 12! But i will tell you this, the PD system is fine, and so is the inter cooler.so my turbo should be alright!!!!!!!!!!!

So i am assuming seth you will have no useful advice to what the problem may be...Well actually i am pretty sure you won't!

 

[seth1]

Hello G, this is a caravan forum,not mechanic on line,seen as how your a "transport manager" have you heard of driver training,probably not because guess what "your right".you might save a good bit on the fuel bill,running costs etc.

But G as a frendly gesture,concerning your boost fault,are you near the cheshire area if so we will gladly plug it up to the diagnostic kit,carry out a vac test,etc at our premises.pehaps bring some professionable friends with you,point us in the right direction.other than that run it into vw.

As said G the offer is there,it will be foc of course.pehaps though G we will have to agree to disagree on some of the above,the statements you,ve made have proved inconclusive,the facts you,ve stated have been wrong,even admitted by yourself,your justifications have been made through here say,or bar talk,the one thing you fail to accept is my company is an apointed,approved factory repair agent.our smallest engine is 3 litres,fitted with CR ,VGT,EGR, if dressed accordingly,

Would you like me to download some FSP files for us all to look at,ie fuel pressures,boost pressure,datalink communication(can data bus)torque on demand,injector status,fuel correction,throttle positions,engine loads, engine torque,etc.the list is endless.

But G my offer still stands to the "BUS"

 

[g_374369443]

I can only say thank you for your kind offer.And if the need arises I would more properly trust you than a few companies around my area, [Leicestershire]

Atm am playing with my Vagcom system, but at work we do have the use of

 

[ShadySadie]

Well thanks for the laughs g

Even I'm still ROFL'ing.

Simple answer for the original question = DIESEL

Nothing was asked about running costs or anything else!

 

[xtrailman]

Shady

Thats why either petrol or diesel will do the job.

Maybe you was laughing while you should have been reading?

In fact i'll stick my neck out and state, if running costs were of no consequence, the petrol turbo would be a clear winner.

 

[ShadySadie]

I read very well, I also read the original question.

The answer is still Diesel to that question as a visit to most caravan sites today will show you.

I have towed with turbo petrol as running costs are not a concern for me. For towing again the DIESEL would be mine and my far more technical husbands choice.

RAY,stick your neck out to often and something may get lopped off ;-)

My husbands latest twin turbo petrol would be no where near as good towing as the same car with diesel. He does not tow with it but he has already decided that he prefers the diesel that will come his way next month.

 

[Lutz]

Judging by the emotive replies from both sides and the way this thread is continuing, it would seem that neither one nor the other comes out as a clear winner and it's basically up to personal preference, subject of course to certain conditions which may be specific to the type of driving one normally does and which may be decisive in the end.

Long live petrol and long live diesel, but I've decided to opt for a hybrid as my next towcar.

 

[xtrailman]

Lutz

If an electric car was available, that would be a clear winner, the starting torque would blow away petrol or diesel.

Sadie lady

Are you seriously saying you prefer to drive a diesel, with the noise they all emit. Over the serene silence of petrol?

 

[Lutz]

Ray, the Lexus 400h hybrid is on the shortlist as my next towcar. It's got a max. towload of 2000kg, so that should be ample for my needs.

 

[ShadySadie]

I've a diesel tow car and a petrol car. David at the moment has a petrol road car and we have both driven the diesel version and prefer it to the petrol. Noise wise there is little difference outside and you don't notice it in the car anyway.

Hybrid with batteries is a non starter. We've never bought into eco spin stories anyway.

Diesel torque is great and we've had great fun testing a V12 Audi diesel. If I can get the right deal

 

[g_374369443]

"Well thanks for the laughs g

Even I'm still ROFL'ing.

Simple answer for the original question = DIESEL

Nothing was asked about running costs or anything else!"

I am glad you had a laugh, that would possibly be the limit to your mentality on this subject!

I am glad that you mentioned Audi in a later post, as they do build some incredible diesel engines, they also build some incredibly good petrol ones with torque response figures right down below 2000 rpm !Max figures that is, with better linuer pick up and power than most day to day diesels have.

Of coarse you understand all this! and what that should mean where towing is concerned,but alas you don't otherwise you wouldn't have bothered making the post I have marked above!

If you want to impress me sadie, why not answer the question I set many days ago concerning towing up an incline, go on show us how the diesel cars supposedly superior low-down torque would win the day!

Go on Sadie say something constructive, or even why not explain why I made you laugh? because I can only think I made you laugh because, this is all over your head.

 

[ShadySadie]

You made me laugh because you hijack so many subjects here g io!

Sadie x

 

[g_374369443]

I am sure that at some time i have hijacked a thread or two,but i am along way short of you sadie on that score. Indeed on this thread it seems after the original post it turned direction,and had nothing to do with me,at first indeed more than a score of post had pasted before i replied to one, note replied! and another score of post changed its direction more than once! So if thats all down to me, and hi jacking a thread, then OK.

So does that mean your posts concerning "make me laugh" should also be deemed hi jacking?

 

[MichaelE]

You would have to get a good deal on an Audi V12 as they will lose nearly 60k over 3 years.

 

[ShadySadie]

You would have to get a good deal on an Audi V12 as they will lose nearly 60k over 3 years.

1. I wouldn't be paying 60k for the car.

2. I will not have it for 3 years.

3. It is an indulgence, cost is not an issue.

 

[MichaelE]

I was just stating how much these big engined cars lose in value these days,3 years is the average but you do lose the bulk of that in the first year.

My sisters husband works for a big Audi dealership.