Ot-They lied

[JIPJOBXX]

I have an article that states the new 1942 Dodge with Fluid drive will get and average of 21.9 miles per gallon! At the present I'm getting 16 but hay I blame it on the gas and of course my pedal to the metal!!!!! No not really but this old heavy weight car runs best at 45 to 50 mph and if I push it much more than that its really staining the power plant. I think allot of this gas consumption is due to the fluid drive and the way it transfers the power to the rear wheels. Its kind of like a bad clutch that just slips till it gets up to speed. Anyway nice day outside and maybe I will burn some expensive gas today in the old Dodge. Jon:D

[James_Douglas]

A fluid coupling is 98% to 99% efficient at transferring the power to the transmission input shaft once it un-stalls at about 6 MPH. Since it does not have a stator it is more efficient than a (non-lockup) torque converter which runs in the low 90's % range.

In my 1947 Desoto Suburban with a curb weight of 4800 pounds and 4 people in the car I recently got 20 MPG on a round trip of 250 miles running at 65 MPH for most of the way.

The car has a 3.91 reared and BW overdrive with a 251 cu.in. engine at 8:1 Compression and a single Carter Carb.

James

[Dodgeb4ya]

I wonder why they use lockup torque converters today? They should go back to Fluid Drive couplings for better mileage?

[JIPJOBXX]

Well you have two things better than mine and that is an overdrive unit and the higher geared rear end. But if I was to put all that stuff in the cost factor probably would never make up for the lower mileage I get. I know how the fluid drive works but when you start out in high that in itself must really suck in the the fuel. With that higher rear end do you start out in high or shift from second to high?

[Plymouthy Adams]

torque convertors and fulid drive couplers are unique and different animals..the coupler does not multiply the engine power and thus the slow but smooth pull away..the torque convertor does multiply torque and by using the lock up the engine RPM can be reduced by 300 RPM (approx) when at 1:1

[JIPJOBXX]

Just wondering do you have the electric type of kick down plungers in your carberator for the fluid drive carberator? I know I'm getting oft the subject matter and will start another tread but just wondering?

[Plymouthy Adams]

as noted..the first torque convertor they used was in the hy-drive..now the muyltiplier (x's 2.6) of the torque made that the gear ratio's in the tranny be a bit taller along with a taller rear gear..3.73 was stock ratio

[suntennis]

On one report of gas milage back in the 40s for a Nash, I recall they were claiming over 20mpg. The report gave gas mileage at different speeds and the one for over 20mpg was around 35mph. The higher the speed, the lower the gas mileage.

[Dodgeb4ya]

Torque converters did not have the TQ lock up feature at least for Chrysler Corp till around 1978 or 1979, and the main purpose was to help MPG. I have a 1952 Hemi NY car with the Fluid Torque Drive- It is such an improvement over the Fluid Drive cars- No comparison even if it was a six! So much more power upon acceleration.

[B-Watson]

Torque converters did not have the TQ lock up feature at least for Chrysler Corp till around 1978 or 1979, and the main purpose was to help MPG. I have a 1952 Hemi NY car with the Fluid Torque Drive- It is such an improvement over the Fluid Drive cars- No comparison even if it was a six! So much more power upon acceleration.

The first automotive application for the torque converter lockup was Packard's Ultramatic in 1949 followed by Studebaker's Automatic (built by Detroit Gear Division of Borg-Warner) in 1950. Both transmissions were dropped by 1957 although the DG transmission was used in Europe for many years.

Chrysler's TC lock-up of 1978 was next. As pointed out, Chrysler's first torque converter appeared for 1951 as Fluid Torque Drive and it did not have lock-up. Plymouth's Hy-Drive was essentially FTD hooked up to a manual transmission instead of the 4-speed semi-automatic.

When it comes to acceleration a torque converter beats a fluid coupling any time due to the torque multiplication. Both Chrysler's semi-automatic and GM's Hydramatic were 4-speed units while all the other transmissions using a torque converter were two or three speed with two of them being a one-speed when in Drive. (And contrary to what one "expert" in Hemmings Classic Car wrote, Buick's Dynaflow did not have a kick-down to low gear for use as a passing gear. In Drive it was truly a one speed.)

[White Spyder]

My two cents and a rant. First I did a 100 mile round trip on the Natchez trace and got 18 mph in my '48 Windsor. Not bad. Now, to the OP statement. Back in the day they were using 100% gas with lead and a higher octane. If I got 18 on regular with 10% ethanol on my trip, I might have gotten 20 if I had been able to find 100% gas. MPG statements by the manufactures today are a hoax. They use 100% gas and the optimum conditions to make their calculations. They do this so they can meet the CAFE standards set by the government. Now, our friends in D.C. are all but mandating blended gas for sale to the public, so John Q will never get the millage on the sticker. Granted there are those out there that have gotten better mileage ON occasion, but that usually involves a technique call hype-rmileing. By the way what do you think your mileage will be with the new limit of 15% ethanol will be? Oh, and did you see that most of the major car companies stated that using 15% blended fuel in non E85 cars will void your warranties?

O.K. I'm stepping down from the box for now.

[greg g]

remember when the Mobile Economy Run was the big deal. Independent drivers would drive new cars over a prescribed route and then report the mileage, and the manufactureres would thump the results i their advirtising. Todays blend of gas is way down on BTU from the stuff of the 60's fewer btu's less thermal efficiency, less TE less mileage. That said, my wife and I took a trip from syracuse to just outside Buffalo to pick up a vehicle for the dealership we work for.

They provided a 2010 Hyundai Sonata for us to ride out and back in, I picked up a Grand Caravan. The Sonata was a base model with not a lot of frills 4 cylinder, and the in dash trip computer (which I know aren't 100% accurate) said 39.4 mph for the trip.

The Caravan which had 6 miles on it was sporting 26.5 mph when I pulled into the dealers lot. I am sure both those numbers beat the widow sticker, even if you allow for a 10% inaccuracy.