Towing economy

[Jerry]

Apart from dodgy fuel economy (22mpg when towing steadily at 65-70mph) Kuga is much more stable than Mondeo (I have both with towbars so good comparison). Kuga sits much higher off the ground than Mondeo and I don't really feel the trailer when towing. AWD in Kuga gets it out of the water without any wheel spins noticed, there is enough torque for motorway overtakes. I would buy Kuga for towing again.

It also keeps SWMBO happy, because it's her car when towing isn't required.

[wellhouse]

BMW x6 4.0, zodiac 550 1.2t on trailer no cover, 29.2mpg. Without trailer 30.1mpg. 313 PS (230 kW; 309 bhp) 630 N·m (465 ft·lbf). (sticking to the speed limit) To be honest you hardly notice the boat is there!

[jonp]

Originally Posted by wellhouse

BMW x6 4.0, zodiac 550 1.2t on trailer no cover, 29.2mpg. Without trailer 30.1mpg. 313 PS (230 kW; 309 bhp) 630 N·m (465 ft·lbf). (sticking to the speed limit) To be honest you hardly notice the boat is there!

That's some pretty decent power, if you put your foot down hard you may be able to turn that 550 pro into. 650

[wellhouse]

Originally Posted by jonp

That's some pretty decent power, if you put your foot down hard you may be able to turn that 550 pro into. 650

0-60 in 5.9s apparently, not tried it but there if i need it! Apart from the new levels of fines for speeding - another incentive if you needed it, the fuel bill goes up significantly if you get heavy with the right foot!

[Jerry]

Originally Posted by wellhouse

0-60 in 5.9s apparently

Is that with the boat? :-)

I'm coming to the conclusion that 2L engine has enough torque for towing, but gets strained a bit. A 6 pot variety won't probably strain because of much bigger power and torque margin.

[SteveHall]

I get about 15MPG with the boat (6.5mtr) on the back of my Outlander PHEV...

[willk]

Originally Posted by Jerry

For fuel economy: Is it better to tow a RIB without a cover but with the light board on an A-frame, or use the boat cover.

It's better to drive between 50 and 60mph - not 70!

It's murdering your mileage and not particularly safe either - IMVHO.

[mikew4]

i can't see that a cover is going to make any material difference to towing fuel economy.

Even less, when you look at at the cost saving of towing with or without cover as a % of your annual boating cost.

[Jerry]

Originally Posted by willk

It's better to drive between 50 and 60mph - not 70!

That's what I thought as well. I went to Port Grimaud 60mph, came back 70mph and mpg was the same. Next time I will try 50-55, but I'll have to find a short trip for it :-)
Safety wise it's ok, the set starts sneaking around 80mph.

[mikew4]

Speed is the wrong measure. For maximum economy, you should drive by the rev counter and keep it at the RPM that delivers maximum torque. This will be detailed in the vehicle handbook.

[9D280]

Originally Posted by Nos4r2

Gotta have a decent cover to tow with one on-the DucksBack ones balloon right up. I tried it once. Never again. .

A cover makes a significant difference on both my 470 dinghy & open box trailer. Having said that, on both of them I can get the top cover nice & taught with no fear of chaffing tubes, and both are arguably more aerodynamic as the rib has a lot of square section bars (the trailer chassis) & stuff to drag through the air. - the 470 although similar length sits on a relatively delicate trailer and doesn't have an A-frame, console etc. poking out & the mast support mostly sits in the "vacuum" behind the hatch (and no, I can't open it without un-hitching due to the mast or the support...)

Originally Posted by Nos4r2

Lights should be on the trailer for legal purposes, and they're probably more secure there too.

I assume you are referring to height off the road for tail, fog etc, before we start that debate again!

Originally Posted by Jerry

Ford Kuga 2.0TDCI 180BHP. It does 40-45mpg solo depending if it's me or the wife driving it.

When towed behind Mondeo (also 2.0 TDCI) it did 25mpg with the boat, 50mpg solo.

Those numbers echo my old 2.0L 130ps Focus

140PS 2.0L Mondeo TDCI, now, and I get 51.5mpg average car alone if I really don't pay attention to the economy & "just drive". Easdale & back I averaged 35.4mpg. Didn't go above 50mph, but that route does involve some hill climbing & unnecessary slowing / accelerating for long sweeping bends with tourists / Caravans in front! (granted knowing the road does help!)

I've not taken the boat behind the Mondeo anywhere with a long motorway tow yet....

Boat is 5m, single axle trailer, towing weight half fuelled is 750Kg.

[Jerry]

Originally Posted by 9D280

A cover makes a significant difference on both my 470 dinghy & open box trailer. Having said that, on both of them I can get the top cover nice & taught with no fear of chaffing tubes

That's the kind of cover that I have - heavy duty cover which fits snugly on the tubes. My cover also goes on top of the A-frame, so I'm not sure if having that cover on will help with drag. This would be one bigger cone going through the air instead of the console and the lightboard.

I assume you are referring to height off the road for tail, fog etc, before we start that debate again!

Exactly, let's not. My question is: do I get myself trailer lights mounted at the bottom and use the cover (can't mount the lightbar on the A-frame when the cover is on), or should I keep towing the RIB without cover and with a lightboard stuck onto the A-frame? The bottom lights would then be submersible LEDs, but I'd have to still make some arrangements for pushing the lights right into the trailer (too lazy to disconnect the lights and take them to one side) for launch/recovery and to extend out for towing. If I mount the lights permanently then those simply won't be visible with the boat on.

Those numbers echo my old 2.0L 130ps Focus

140PS 2.0L Mondeo TDCI, now, and I get 51.5mpg average car alone if I really don't pay attention to the economy & "just drive". Easdale & back I averaged 35.4mpg. Didn't go above 50mph, but that route does involve some hill climbing & unnecessary slowing / accelerating for long sweeping bends with tourists / Caravans in front! (granted knowing the road does help!)

OK, so I have another comparison point. I came back from Lymington to Cambridge on B/H Monday and the traffic very effectively limited my speed to 50-55mph. I also drove gentle, trying to get the opportunity to see the difference. The result was 28mpg. The boat hasn't seen the weigh bridge yet, if/when it does I'll post the numbers.

[willk]

Originally Posted by Jerry

OK, so I have another comparison point. I came back from Lymington to Cambridge on B/H Monday and the traffic very effectively limited my speed to 50-55mph. I also drove gentle, trying to get the opportunity to see the difference. The result was 28mpg. The boat hasn't seen the weigh bridge yet, if/when it does I'll post the numbers.

Why am I not surprised?

If you tow around and below 55mph you'll find that your economy is better and curiously, you won't loose much time either AND you'll be safer - crash stopping a boat trailer at 75mph takes a bit of doing. I know it's obvious, but if you can "drive ahead" a bit and reduce the amount of acceleration and braking you do, it will improve the mpg even more. I reckon even a petrolhead like you could be trained to manage 30mpg

[Jerry]

Originally Posted by willk

Why am I not surprised?
I know it's obvious, but if you can "drive ahead" a bit and reduce the amount of acceleration and braking you do, it will improve the mpg even more.

That's exactly what I've done (I reckon I could've had a full pint on the dash and it wouldn't spill - I was so gentle and forward-looking). What I don't get (and attribute it to either crap trailer setup or aerodynamics of the RIB) is that I was getting better mpg when towing a 2000kg, 7m long sailing boat. Admittedly that was 15 years ago in a different country, using cars which were much less refined than the modern ones. Towing that boat with an E250D Merc back then was giving me 28mpg when towing at 55-60mph. I was just expecting that a 15 years more modern car and a relatively light boat will produce better consumption. I was really surprised to see no difference.

[Maximus]

Originally Posted by Jerry

That's exactly what I've done (I reckon I could've had a full pint on the dash and it wouldn't spill - I was so gentle and forward-looking). What I don't get (and attribute it to either crap trailer setup or aerodynamics of the RIB) is that I was getting better mpg when towing a 2000kg, 7m long sailing boat. Admittedly that was 15 years ago in a different country, using cars which were much less refined than the modern ones. Towing that boat with an E250D Merc back then was giving me 28mpg when towing at 55-60mph. I was just expecting that a 15 years more modern car and a relatively light boat will produce better consumption. I was really surprised to see no difference.

You need to get out more Mate

[Pikey Dave]

Originally Posted by Maximus

You need to get out more Mate

I disagree, I find if I leave the car & boat in the garden, it uses next to no fuel[emoji848]

[Jerry]

Originally Posted by Maximus

You need to get out more Mate

Did that, burned 120L of petrol last Monday :-)
Btw, Scott from Ribrepair did a very good job fixing previous repair which was disintegrating itself.

Originally Posted by Pikey Dave

I disagree, I find if I leave the car & boat in the garden, it uses next to no fuel[emoji848]

[Last Tango]

Some contemplative theory.......

If you don't tow very far to launch the difference in MPG (23, 25, 28 whatever) ain't going to to make much difference to the cost of the day out,

If you're towing a long way, chances are you're away for a few days and what the boat's going to burn in those few days will make any light footed towing economy seem like a futile gesture.

Keep the towing speed down for safety but don't kid yourself it's going to make any real difference to the overall cost.

[mikew4]

Originally Posted by Last Tango

Some contemplative theory.......

If you don't tow very far to launch the difference in MPG (23, 25, 28 whatever) ain't going to to make much difference to the cost of the day out,

If you're towing a long way, chances are you're away for a few days and what the boat's going to burn in those few days will make any light footed towing economy seem like a futile gesture.

Keep the towing speed down for safety but don't kid yourself it's going to make any real difference to the overall cost.

+1