Gas mileage

50C8DAN

Well I finally got a chance to do some relatively long range driving to and from Hershey with a detour to Carlisle to have dinner with the HETers. My '50C8 averaged a bit over 18.5 mpg, running between 60 and 65 most of the time. This is with a 4:56 rear due to the Supermatic setup. I did not think this was too bad!

[Deleted User]

Dan,



That is pretty good mieage with a 4.56! Wow. What RPM were you at driveing 65 mph?

RL Chilton

Too bad?? Heck, no! Most folks are lucky to get 16mpg out of a step-down . . . that's probably with a Twin-H, singles should get a little better, I imagine. Sounds like it's tuned properly to me, that's really pretty good mileage.

50C8DAN

I don't know the RPM since there is no tach. I really tried to keep it down however, if I get near 70 or over you can hear the engine whine quite a bit. I have thought a few times of dropping the ratio to 4:11 which was an option for the Supermatic cars. With 4:11 I think I could crank up the speed a bit and still get pretty good mileage.



An older fellow down the road from me used to have a '52 Hornet with a 308 w/ 3spd and overdrive. He dropped a 3:07 or something there abouts. He got 25+ on long drives. I am not sure how well it liked long grades however.

[Deleted User]

For comparison... My freshly rebuilt 54 Hornet with twin H and Hydramatic was driven 1200 miles to break it in and then I set off to drive from Omaha Ne to Abilene,Texas. The trip began in late afternoon and ended in the early hours of the next day. Speeds were constantly in excess of 60 usually around 70 and the route other than the begining was secondary roads. The Hornet averaged 23 mpg for the trip. Later trips of similar non stop long distances reaffirmed the mileage. I used the cheapest gas available and no additives... tune for the car was factory specs.

Uncle Josh

I calculated my Commadore with 4.56 and 27% overdrive to be 2200 at 60 mph. Adding the 27% without OD gives you about 2800 rpm

terraplane8

That sounds quite good and equates to 20.8mpg imperial which is a fair bit better than my '36H8 does. The strange thing is that the '37 Hudson Eight that set the 24hr and 1,000 mile records on the salt was reckoned by the AAA to be giving 20mpg at 88.9mph average. That's basically at full throttle with a lot of wind resistance too. Goes to show they were definitely not over-carbureted!!

Jon B

Dan, as I mentioned to you at Hershey (and I'll mention here for the benefit of everyone else), when I installed OD on my '37 Terraplane I opted to leave the 4.11 (standard) rearend gears in the car, instead of changing to the 4.56 gears (which Hudson used when an OD was installed). My car has only 101 hp, much less than a Hornet or Commodore Eight, yet the combo of 4.11 and OD still works well on most highways except for some of those long hills on I-68 out in West Virginia. With the newer, more powerful Hudsons, I think that combo would work just fine. I only manage to get about 18 MPG "highway" mileage, but at least that's an honest 18 mpg (averaged over several tankfuls on long trips over varying terrain, with speedo error calculated). Some of Hudson's published gas economy figures came from running their cars on the salt flats at 30 mph!

[Deleted User]

I am going to have to learn the secrets of tuning a 308 Twin-H. On my 1200 trip home with my 52 Hornet I did the math every time we filled up and it averged between 10-12 MPG.

[Deleted User]

mjsandbe wrote:

I am going to have to learn the secrets of tuning a 308 Twin-H. On my 1200 trip home with my 52 Hornet I did the math every time we filled up and it averged between 10-12 MPG.

Michael go to my website ... link below... you will find the information needed to set up your Twin H there. Be mindful of the need to assure your transmission is properly adjusted as well as all other turning elements of the suspension.

Good Luck

Park_W

Our '51 Hornet ragtop with Twin-H covered 2,240 miles in July, to Pontiac and thereabouts and back home. Averaged 18.7 for the whole trip, some of which was not highway driving. This is with 3.73 gears and OD. I drive 65 on the Interstates.



By the way, for you RPM calculators, the Hudson overdrives have 30% reduction, not 27%.