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Re: Interesting tow cars
Posted: Thu Sep 26, 2019 9:33 am
by JLv3.0
On the rather shaky premise that a Defender and a old-shape Wrangler are probably equally well assembled and have similarly advanced mechanicals (i.e. not at all and prehistoric) think more like 50% loss - yes really. A mate of mine ran a workshop modifying Wranglers and the 200 bhp crank figure was more like 100 bhp at the wheels on the dyno.
Re: Interesting tow cars
Posted: Thu Sep 26, 2019 9:35 am
by V8Granite
There is a towing channel on YouTube where they tow 6 horse horse boxes and other such big stuff. It’s amazing how much some of the dually equipped trucks can tow in America. If you are doing 40mph full throttle in a 450hp diesel pick-up, it seems a bit too portly to me
Towing with a 5th wheel must feel completely different though.
Dave!
Re: Interesting tow cars
Posted: Thu Sep 26, 2019 9:40 am
by V8Granite
JLv3.0 wrote: Thu Sep 26, 2019 9:33 am
On the rather shaky premise that a Defender and a old-shape Wrangler are probably equally well assembled and have similarly advanced mechanicals (i.e. not at all and prehistoric) think more like 50% loss - yes really. A mate of mine ran a workshop modifying Wranglers and the 200 bhp crank figure was more like 100 bhp at the wheels on the dyno.
I’ve read a 33% measured loss for a V8 petrol with the same gearboxes as mine but I don’t know what axles it had, probably standard Rover axles.
I’m intrigued now so I’ll find a graph from somewhere.
The Humvee went from 230hp to less than 100ho at the tyres.
Dave!
Re: Interesting tow cars
Posted: Thu Sep 26, 2019 9:46 am
by 16vCento
What about an XC90 V8, I believe a certain member of this establishment used to have one.
Not sure if Mr Yu still has his or not, would probably make light work of a car trailer and sound quite nice whilst doing so.
Re: Interesting tow cars
Posted: Thu Sep 26, 2019 9:54 am
by Sundayjumper
V8Granite wrote: Thu Sep 26, 2019 7:46 am
I’d say that the drivetrain loss is very optimistic, I think closer to 30% is more likely.
Mine has hit a GPS verifies 86mph but that’s on the governor in top, maybe I had an extra couple of mph with different gearing but not much.
Changing the drivetrain loss to 30% I get 88mph as theoretical top speed. For comparison, plugging in numbers for the Touareg, I get 141mph vs. VW's quoted figure of 144mph. So that part of the calc all feels about right within a couple of percent.
Re: Interesting tow cars
Posted: Thu Sep 26, 2019 11:31 am
by V8Granite
That seems far more likely speed wise.
Dave!
Re: Interesting tow cars
Posted: Thu Sep 26, 2019 5:31 pm
by Foz
Re: Interesting tow cars
Posted: Thu Sep 26, 2019 5:40 pm
by Sundayjumper
Foz wrote: Thu Sep 26, 2019 5:31 pm
I can't believe I didn't think of that. It's on my list.
https://www.pistonheads.com/features/ph ... roes/37039
They also did the Touareg with the W12 for a while, but only LHD sadly.
Re: Interesting tow cars
Posted: Thu Sep 26, 2019 5:53 pm
by JonMad
NIce, from someone looking at the SQ7 recently.
As per one of the PH comments on that link, what about
https://www.autotrader.co.uk/classified ... 9051899048 with a towbar?
Re: Interesting tow cars
Posted: Thu Sep 26, 2019 9:03 pm
by Foz
738ft/lb, that’s ridiculous!
Re: Interesting tow cars
Posted: Thu Sep 26, 2019 9:11 pm
by JonMad
https://www.autotrader.co.uk/classified ... 4197153774
or
https://www.autotrader.co.uk/classified ... 9202456899
for £8.5k less from the same dealer, with only the 240bhp and 400lb ft to push you along.
Actually, that's almost exactly half the power of the V12

Re: Interesting tow cars
Posted: Thu Sep 26, 2019 9:49 pm
by Nathan
JLv3.0 wrote: Thu Sep 26, 2019 9:33 am
On the rather shaky premise that a Defender and a old-shape Wrangler are probably equally well assembled and have similarly advanced mechanicals (i.e. not at all and prehistoric) think more like 50% loss - yes really. A mate of mine ran a workshop modifying Wranglers and the 200 bhp crank figure was more like 100 bhp at the wheels on the dyno.
I could believe that.
I remember being a Wrangler 4.0, made a lot of noise on kickdown but didn't really move.
Re: Interesting tow cars
Posted: Thu Sep 26, 2019 11:29 pm
by dinny_g
Foz wrote: Thu Sep 26, 2019 5:31 pm
Wasn’t there a fundamental flaw with the V12 Tdi’s though - 5000 mile service intervals or 2 miles per gallon or summat. IIRC it was little more than a marketing exercise off the back of Le Mans success... R8 first then these???
Re: Interesting tow cars
Posted: Fri Sep 27, 2019 2:07 am
by nuttinnew
Well, the V12 is just two A4 engines cellotaped together.
If rarity (potential costs/aggro) puts you off the V12 but the V6 doesn't have enough oomph, how about this?
https://www.autotrader.co.uk/classified ... 500&page=3
Re: Interesting tow cars
Posted: Fri Sep 27, 2019 9:05 am
by Jobbo
If you want a silly engined VAG and a V8 is too small but a V12 is too big, and a normal V10 is not enough, how about a Touareg R50
https://www.autotrader.co.uk/classified ... 8080942023
Frankly the Q7 V8 TDI is far more appealing though, and I don't like Q7s. Back to the Allroad BiTDI for me.
Re: Interesting tow cars
Posted: Fri Sep 27, 2019 9:42 am
by Nathan
Jobbo wrote: Fri Sep 27, 2019 9:05 am
If you want a silly engined VAG and a V8 is too small but a V12 is too big, and a normal V10 is not enough, how about a Touareg R50
https://www.autotrader.co.uk/classified ... 8080942023
Frankly the Q7 V8 TDI is far more appealing though, and I don't like Q7s. Back to the Allroad BiTDI for me.
Would that 2015 Q7 have the Porsche Diesel engine by any chance ?
Re: Interesting tow cars
Posted: Fri Sep 27, 2019 9:52 am
by Jobbo
Nathan wrote: Fri Sep 27, 2019 9:42 am
Jobbo wrote: Fri Sep 27, 2019 9:05 am
If you want a silly engined VAG and a V8 is too small but a V12 is too big, and a normal V10 is not enough, how about a Touareg R50
https://www.autotrader.co.uk/classified ... 8080942023
Frankly the Q7 V8 TDI is far more appealing though, and I don't like Q7s. Back to the Allroad BiTDI for me.
Would that 2015 Q7 have the Porsche Diesel engine by any chance ?
I have no idea - I didn't even realise they kept making a V8 TDI that late. This Autocar article from 2009 (when the Q7 was facelifted) says the 4.2 got a power increase, so it may simply be that they kept fitting the same slightly tweaked Audi engine from 2009-2016:
https://www.autocar.co.uk/car-review/au ... -v8-tdi-se
ETA: Porsche used the Audi engine anyway, not sure how they modified it themselves so it's possible Porsche's mods made it into the Audi version I guess...
Re: Interesting tow cars
Posted: Fri Sep 27, 2019 10:21 am
by JonMad
Re: Interesting tow cars
Posted: Fri Sep 27, 2019 10:25 am
by V8Granite
Panamera V8 tdi was supposed to be quite special. There was an owner on readers cars in Pistonheads.
Dave!
Re: Interesting tow cars
Posted: Fri Sep 27, 2019 10:39 am
by Foz
When did the current panamera appear, 2016 was it?