Two heads better than one? - Fuel Economy, Hypermiling, EcoModding News and Forum

ShadeTreeMech · 05-29-2009, 11:57 PM

I have a 97 Mercury Villager minivan that, I'm told, has a power robbing wake. I also have a broke down 95 Ford Escort 5 speed that is lucky to get 30 mpg, but it has way too much torque for its own good. I'm planning a trip that may cover around 5000 miles, but my van is a bit cramped. I was figuring on a very small trailer, or using an open boat tail that is built to hold extra luggage. I also considered hitching the Escort to the rear of the minivan to use as a bit of a trailer/ extra vehicle, and that got me to thinking. I know that Escort can pull a 2 ton vehicle down the road; not quickly, but it is capable of it.

Suppose I were to get behind the wheel of the Escort, and whenever the wife got up to speed, I could put the Escort in gear, and she could put the van in neutral, letting the engine idle while the Escort did the hard bit of keeping the vehicles moving at, say, 60 mph. The Escort has a smaller engine, plus the manual gearbox instead of the auto. Would there be any way to guesstimate the combined fuel economy of such an arrangement? Or maybe even leaving the van in gear, but it doesn't have to work as hard since the Escort is helping to push.

Any ideas?

Frank Lee · 05-30-2009, 02:39 AM

Tag team driving with the wife? Don't go there.

Daox · 05-30-2009, 08:04 AM

Sounds like a disaster waiting to happen.

aerohead · 05-30-2009, 01:47 PM

Your instincts are probably dead on with respect to Escort's efficiency but the safety issue completely overshadows any potential benefit.As the others have said,don't go there!------------ The cost of pulling the Escort would cancel any gains as a trailer.Consider a light trailer or,if you have a receiver-type trailer hitch,consider buying a $50 cargo platform and fabricating the boat tail enclosure as part of it to carry light bulky gear.You can take it off at destinations for local running around,then slip it back on for the longer legs of the trip.18-inches of boat tail got me an extra 4-mpg with my VW van.

ShadeTreeMech · 05-30-2009, 03:43 PM

My question is this, what safety issues? I'm talking about 2 licensed drivers, and I'm not talking about the kind of torque from the Escort that could cause a 50 mph jackknife, just enough to keep the thing rolling. And my alternative method would have the van pulling part of the load. But my curiosity is this; does anyone have the ability to calculate the mpg, considering the van and car would be sharing the same air, and so the car would have almost no wind resistance.

There are bendy buses in the UK, the type that bend in the middle but are very long, that have the engine in the rear. And they manage that alright, so why wouldn't a car with an engine too small for the job do alright doing the maintaining speed bit? I'm not trying to start an argument, and I'm only halfway playing with the idea. But the physics ought to be fun to play with, and I'd hoped someone with theoretical curiosity would have fun sorting this out.

aerohead · 05-30-2009, 04:04 PM

Quote:

Originally Posted by ShadeTreeMech

My question is this, what safety issues? I'm talking about 2 licensed drivers, and I'm not talking about the kind of torque from the Escort that could cause a 50 mph jackknife, just enough to keep the thing rolling. And my alternative method would have the van pulling part of the load. But my curiosity is this; does anyone have the ability to calculate the mpg, considering the van and car would be sharing the same air, and so the car would have almost no wind resistance.

There are bendy buses in the UK, the type that bend in the middle but are very long, that have the engine in the rear. And they manage that alright, so why wouldn't a car with an engine too small for the job do alright doing the maintaining speed bit? I'm not trying to start an argument, and I'm only halfway playing with the idea. But the physics ought to be fun to play with, and I'd hoped someone with theoretical curiosity would have fun sorting this out.

Some fairly recent automobile crash safety research conducted by Mercedes indicated that serious injury and death occur in a matter of 200-milliseconds. With your 2-car NASCAR configuration,once your wife reacted to a traffic situation,the time horizon for any reaction to actually begin would be TWICE the normal span, do to your reaction time.You increase jeopardy for both you and your wife.With you "blind" to what is happening ahead,your already at the accident scene before you even know it's occuring,rear-ending your wife while under power as she's in the process of full lock-up braking and colliding.And correct me if I'm wrong,but I believe it is against the law in all 50-States for anyone to occupy a "trailer" as it is being towed.

Bicycle Bob · 05-30-2009, 05:44 PM

Around here, we see all kinds of odd combinations on the almost empty roads. Assuming a normal tow rig, the van does all the steering, and only needs the car brakes in an emergency. Extra caution would probably keep the risk to normal levels, except for official interest in the legalities.

The combined mileage is hard to predict, but I'm sure the best option would be a trailer that works as a tapered tail for the van, with sliding panels across the gap.

ShadeTreeMech · 05-31-2009, 01:14 AM

I suppose the main reason for me even thinking about this is the underpowered nature of the van as it is. It has a hard time maintaining 50 mph in overdrive when going up a mild hill. Once I get over about 65, the revs are around 2200, and so downshifting isn't much of an issue. The only thing is spinning that V-6 that fast for so long annoys me. I wish it had a better tranny.

Unfortunately my finances are somewhat limited, which brought out the whole "use the car as a trailer" thing. And I think bicycle bob knows what I'm thinking about but Aerohead isn't so sure. I'm talking about putting one of those tow bars on the front of the Escort like what you see on small vehicles being pulled by a RV.

What is that general rule about adding weight reducing the fuel economy? Isn't it like 1 or 2% for every extra 100 pounds?

bgd73 · 05-31-2009, 01:21 AM

I see what you are saying. The minivan and cutting wind is a hoax. if it were the van and a long nose tractor trailer behind it, it is cutting a wedge. else, your spanking your torqy escort. Which is quite odd to hear, an escort with torque, I drove four of them, from the 80s into mid 90s. I would rather a 4000 pound overheating slant six dodge with 90hp, or an old sube. if the escort could haul (and that is insane to think about...watch those magnesium head fires) then the escort would be the wedge for the taller van.

just drive both seperate, or strain the escort to haul the van...and I sure as heck wouldn't even try it.

ShadeTreeMech · 05-31-2009, 01:29 AM

yeah, that little Escort really is something else. I'm not sure if it just the gearing or what, but that thing will burn both tires in the dry from a dead stop. And as I did mention, it pulled a Ford Explorer for about 2 miles without complaining too badly. So I suppose it may just be an unusual little car.

Funny thing is, it is absolutely horrid in the snow and ice. I had an 83 Nissan Sentra wagon that could drive circles around many a 4WD in the snow, and it was just front wheel drive.