Towing cars and BPH
I've got a Sterling Eccles Sapphire, 2008, 5 berth and a Mondeo ST 2.2 CDTI car.
At the weekend we did some very steep climbs and descents up in North Scotland which has resulted in our car bellowing black smoke and kangaroo fuel if the revs climb too high 
We are looking to buy an older car or 4x4 as workhorse for towing but I can get the weights etc all to balance out on a 2.5 engine but the BPH always comes in with an advisory caution - does this really matter?
New to towing / caravaning so any advice you can offer would be great!
Caravan details in photo below.
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It will matter on hills, as you have found!
What sort of BHP are you thinking of?
We had an XC90, BHP was 184, it towed our Sterling twin axle MTPLM 1900kg OK, was better with our previous Sterling which was MTPLM 1300kg.
We recently swapped to a VW Touareg, 3 litre diesel, BHP is significantly higher, about 262 I think, and it fairly shoots up the hills, a very marked difference!
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I have no trouble towing our 1500kg 'van with our 136 BHP X-Trail. Wasn't the guide foemula 40BHP per tonne? Our car is 1725kg with just me in it and so with OH and the stuff carried probably less than 2000kg. The ormula would sugest for me 140BHP which is close. I have stopped and started on a one in five so happy enough,
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Having looked up the BHP for a mondo 2.2 ST it is given as 155 bhp in std trim.
i would have thought that was fully capable of pulling away uphill with 1560 kg attached.
it would seem you need to get the car engine and drive train looked at as a matter of urgency.
black smoke and kangaroo antics are nothing to do with occasional hill climbs unless severe overheating is occurring or the mechanics of engine need attention.
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BHP is Benign prostatic hyperplasia, an increase in size of the prostate in middle-aged and elderly men.
This thread seems to be instead about Brake Horse Power, for which the correct acrynoym is Bhp.
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And the edit timeout stops BHP becoming BPH in order to make sense.
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It's horsepower that gets you up the hill, not torque.
There's something seriously wrong with a car that has 330bhp if it can't pull even the largest twin axle caravan. Perhaps one should try dropping a gear or two. For a number of years I towed a 1300kg caravan behind a 90bhp petrol engined car and that got me up every hill that I ever had to negotiate. Lately I used a 270bhp petrol to tow an 1800kg caravan and that was easily more than enough to move with the traffic flow.
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To be fair to nutsy, he said his car is only 1000kgs ..... not many twin axle caravans less than that. My Smart has 84bhp, but weighs around 850kg ..... aside from not being type approved, I doubt it'd tow very well ....
My diseasal tow car 'only' has 224bhp but has 375-ish ft/lbs and towns very well. Previous car was petrol, had around 200 of both but nothing like as good as the R320
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All depends where the power is produced. Ya need both really: A performance motor produces its power hi up, but may not have much low down power: But most have a good happy medium. A deisel produces low down so good for setting of but soon run out of steam. Thats why they dont rev high. A good 2L petrol will out perform deisels every time. specialy on hills. Or in a race:
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Horsepower is basically torque times engine revs, so you can't have power without torque.
Modern twin turbo petrol engines are quite as capable of producing maximum torques at the same sort of engine speed as an equivalent diesel. The idea that a petrol is inferior is a carry-over of days gone by.
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Just looked up the specs for the OP's car and it should be more than capable. I would get it to a garage and checked out, one of the things I would be asking them to do would be check the engines back pressure with a view to the fault being a blocked / partially blocked DPF.
Mad Max, Diesels don't rev high because they would self destruct, so are governed. Without going in to great detail, this is because a Diesel is a Compression Ignition engine and has a much higher compression ratio than a Petrol, which is a Spark Ignition engine. Because of this the Diesel engine has to be constructed to withstand the higher forces created during combustion and as a result they are generally heaver. The heavier spinning mass of it's components therefore restrict has fast you can let it spin.
Having seen a few runaway diesels in my working life rev out of control, I can assure you it's quite a spectacular thing to watch, but only from a safe distance
That's of course if the amount of smoke generated doesn't block your view.
In simple terms. "It's the horses that do the pushing and pulling but the torque has to start it all happening"
I have also noticed that these debates always focus on the engine output but never mention gearing which also plays a major part.
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Mad Max, Diesels don't rev high because they would self destruct, so are governed. Without going in to great detail, this is because a Diesel is a Compression Ignition engine and has a much higher compression ratio than a Petrol, which is a Spark Ignition engine. Because of this the Diesel engine has to be constructed to withstand the higher forces created during combustion and as a result they are generally heaver. The heavier spinning mass of it's components therefore restrict has fast you can let it spin
Diesel engines don't rev as high as petrol engines purely because diesel by its very nature, burns more slowly than petrol. Whilst your description of how it ignites is correct, diesel engines are not limited by their construction, but purely by how the fuel burns. When a diesel overruns, it is usually because it is feeding on the lubrication oil, usually from a blown turbo seal. Diesel fuel on its own won't cause an overrun, it has to have an unintended supplementary fuel for this to occur. Diesel engines are governed because beyond a certain RPM, the fuel will cease to burn at the designed compression which will cause poor running.
And torque (nm) is what you need for towing, of which most turbo diesels have plenty. Bhp is largely irrelevant
This is a misnomer often quoted by people who tow. BHP is very relevant, given that it is directly linked to available torque.
HP = Torque x RPM/5252
The only advantage of high torque at lower rpm for towing is fuel efficiency and less requirement to change gear to keep the engine within it's optimum range of the above equation.
At the weekend we did some very steep climbs and descents up in North Scotland which has resulted in our car bellowing black smoke and kangaroo fuel if the revs climb too high
Get the EGR checked, common fault with this engine
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Honda CRV 2.2 dti, 150hp and a strong tug. 100kg nose weight. Currently in the highlands and hasn't missed a beat. Returning 31.6 mpg. In Czech Repulic we stay in a campsite at 2500 feet, no problem. Our van is only 1350kg but suspect their wouldn't be much of a performance drop off at 1500kg. I normally keep a car 2 years but this has been such a superb tug that it is now nearl 6 years old and cover nearly 70k miles of towing.
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Is everyone about to start quoting figures, the benefits and a personal mini review of their own chosen chariot of choice?
OK... heres mine. Range Rover Sport TDV8. 270BHP and 640NM of torque. Fuel economy is dreadful but I don't care, I didn't buy this car to penny pinch. It's not the most reliable car on the planet either, but I don't care about that too. The way it drives, goes, looks and sounds more than makes up for it's little foibles.
Reliable and frugal, so boring
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Nigel, I did say without going in to great detail Yes I could have put about the rate of burn, initial, rapid etc after ignition. Or even more modern systems with pre, pilot and post injection. I think you would have to agree between us we have now given the full story. I stand by my statement based on what Mr C&G taught me at College back in the late 70's.
Re the run away. I agree that self fueling is a cause, and It was not uncommon on the original AEC engine in the Routemasters. but in my many years in the workshops where we maintained a fleet of nearly 2000 vehicles (I worked in the London Bus industry) I like to think I saw most things that could go wrong including injection pump governors failing causing runaways, this was mainly on Leyland 680 engines and (I can't remember its designation) but the Horizontal engine with integrated cylinder head Leyland Introduced. Fuel pump types were Min/Max and All Speed governors. When one gave up it would usually result in one of two outcomes. Either a thrown rod or seizure. Funny thing was the company advise was to put a hammer through the Ali sump to drain the oil to try and stop it if it was burning it's oil. Never saw anyone brave enough to attempt though,
As an aside if you want to see a good example of strong construction of a diesel have a look at the engineering in a Gardner 6LXB , 11L Max RPM 1850 but would pull a house down. It even has rods that pass through the crankcase and main bearing caps to sure it up. Triple link timing chain. Cam lobes that can be unbolted and changed,,,,,,,,,,,,,
Sorry for rambling on Nice car BTW
Oh, and Freelander 2 SD 190BHP & 310ftlbs
And a 73 Triumph Stag.0 -
Can't argue with any of that, you clearly know your stuff. Just wanted to highlight why diesels run slower, not as a result of the fact they have to be designed stronger and heavier, but because all of this is primarily down to the way diesel performs as a fuel. Cause and effect if you like.
The idea of owning a classic again is pulling me back to classifieds once more. Old British like the Stag is a lovely car to own (are you on first name terms with Rimmers yet?) but not my thing. I had an Alfa Alfetta GTV6 (1982) and loved it but had to sell to fund my decision to go self employed. Now craving for another and have started searching. There's a few out there but the right one hasn't appeared yet. When it does, I'll be on it like a shot.
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The idea of owning a classic again is pulling me back to classifieds once more. Old British like the Stag is a lovely car to own (are you on first name terms with Rimmers yet?) but not my thing. I had an Alfa Alfetta GTV6 (1982) and loved it but had to sell to fund my decision to go self employed. Now craving for another and have started searching. There's a few out there but the right one hasn't appeared yet. When it does, I'll be on it like a shot.
Go for it. a boy's got to have his toy's. The "Brothers" as they are known are not mine, or others I know, first port of call for parts. Dearer than most and some of it is poor quality.
Here's mine. A lot of blood, sweat and tears. and Money
but its great fun. I even know a couple of owners that pull older, lighter caravans with them.Sorry to the OP for digressing from the topic a little
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Sounds like the advice to get the car checked! Haven't a clue what the HP was but back in 1971 toured Scotland in a 1256cc petrol Viva, pulling a Sprite Alpine - no probs at all! If you want hills though, there are far worse in the UK than in Scotland. When we moved from the Highlands to West Yorkshire, we sold our bikes because the hills were far steeper!
Can still remember Club advice in En Route (remember that?) when a member queried if he would have any problems with towing up hills if he went abroad. Advice was to head to Dover via Folkestone - if you could manage that, there wouldn't be problems abroad!
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