Hi David & Craig, For the sake of argument (indulge me); At 10:50 PM -0400 4/25/02, David Fann wrote:

An auto expert with Popular Mechanics wrote many years ago, in answer to the automatic vs. standard question, something like "An automatic transmission will deliver at least five times more starting torque than the best-educated clutch foot with a manual transmission." That has pretty much been my experience over the years.

So how much time do you spend using starting torque? And how much actually towing the vehicle? A manual tranny is a direct connection to the wheels; it only slips when starting, and it's true, it's dependant on the operator. An automatic is slipping ALL the time while you drive, no matter how you cut it, except for the clutches in modern transmissions that engage a direct connection. They do not engage when pulling a load, except when going downhill. Pulling a trailer, you may achieve as low as 60% efficiency from the engine to the drive wheels while a manual stays at 100%. This is why transmission coolers are mandatory on auto tranny's pulling trailers, it's hell on them. On 4/25/02 9:58 PM, "Honshells" <chonshell@ia4u.net> wrote:

Thanks, Harvey: That reminds me of another question I wanted to ask. What is the consensus on towing with an automatic, rather than a standard, transmission? Seems to me, a standard would be a challenge on a slick boat ramp, however, standard transmissions are cheaper to buy, cheaper to fix and better on gas mileage. Anyone? Also, I broached the same tongue-weight question in a different way last year and remember someone saying something about adding a transmission cooler: Would anyone recommend this modification to a tow vehicle and, if so, is it an expensive addition? --Craig

Yes Craig, if you pull a trailer, and have an automatic, you need a transmission cooler. It's so cheap & easy to put in you won't believe it. Yep, a manual tranny is cheaper to buy, cheaper to fix and better on gas mileage. But unless you are comfortable with them in any situation, you should either practice more, or get an automatic. I personally love the control of a clutch. As far as tongue weight, if your hitch is rated at 200# and your static tongue weight is less than that, you're cool. If not, put some weight in the back (beer cooler) of the boat (or take some out of the front) & tie it down, till it's right. Careful though; keep about 60% of the weight in the front. unless you want the rear tires of your car to leave the ground, or for the vehicles to jack knife. I've seen it. On an M15, doing the math, that looks to me like a minimum tongue weight of approximately 175# (considering the trailer weight as well). Anyway... back to torque... unless you hit a stoplight every other block, physics are working against you. And while The torque statement MAY be correct, it doesn't address starting efficiency, just torque; gas costs money. On an auto tranny, the engine is allowed to rev to its optimal torque RPM while the vehicle resists Newton's second law of motion (A=F/M or F=MA (A= Acceleration F= force M= mass)). And while this may produce optimal starting torque, auto tranny's are tuned to the approximate loaded weight (mass) of the vehicle; with a trailer to pull, the mass increases, and the slippage involved may compromise an already slippery situation. A strong pop of the clutch may be more efficient. Ford discourages using overdrive on the auto tranny's while pulling trailers; because of the possibility of too much slip = rising internal temps = tranny failure. That limits you to about 55 MPH and an engine that's revving pretty high. I'd rather be more in control of my destiny with a simple downshift when needed. Just my three cents. I guess I have too much auto tranny rebuilding experience to let that one go... (sigh) so with that said... I tow my M15 with either a '92 Ford E150 Waldoch conversion van, or an '88 Merkur Scorpio, both with auto tranny's. Neither has any problem with towing the M15, can't even feel it behind the van. I have standard transmission vehicles, but... I think the best vehicle to tow a boat is... the one that has the hitch on it. So much for my transmission rant... ! -- Cal Spooner M15 #402 spoon@visi.com cspooner@mn.rr.com 763.574.1482

At 10:00 AM -0400 4/26/02, David Fann wrote:

Some automatics have a locking (non-slipping) top gear. That would likely be a good choice for trailering.

I addressed this in my reply... it's not a "top gear", but a clutch that engages when conditions are right (speed is maintained easily with little load) and it locks the transmission into a 1:1 ratio. Manufacterers of vehicles that have these transmissions discourage you from using this feature while pulling a load, as the clutch will engage/disengage as conditions change (i.e. uphill/ downhill) and cause unnecessary wear on the internal clutch. It also jerks you around quite a bit as the clutch pops in and out. These kinds of transmissions are not found in trucks for the most part because they don't work under load. The closest thing in a truck is the Ford overdrive, which Ford recommends you turn off while towing. Kinda defeats the whole purpose. My M15 is light enough that it doesn't make a difference... I can keep it in overdrive most of the time. But when I lent it to a friend that had a heavier trailer, he came back to me telling me that my fuel injected 3.0L V8/C6 combo didn't have the guts to haul it. He complained of it jerking, surging, bogging down, etc. I showed him the little button on the end of the shift lever that disables the overdrive. He hasn't had a problem since. -- Cal Spooner M15 #402 spoon@visi.com cspooner@mn.rr.com 763.574.1482