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MPG

Started by Lexi, May 13, 2023, 01:37:58 PM

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Lexi

I took Lexi out today for a combination of highway and in town driving, (no stop and go traffic experienced just some stop lights). Mileage clocked out at her best ever at 22.46 mpg (Imperial gallons), or 21 (US gallons). Top speed was 72 on the highway, maxed, with average probably around 65. That has got to be good for this massive 1950s Limo beast. That was on high octane fuel mixed between 93 and 94. Believe all is ethanol free. Trying burn off fuel from when parked last fall, did add some fresh gas as well. Does anyone else check their mileage and what is expected for classic Caddies in various eras?

"Cadillac Kid" Greg Surfas 15364

I check the mileage frequently enough to know when the vacuum advance needs replacing. Mileage on my 75/76 coupes drops from about 12/13 to 7.5.
My wife driving my 72 Eldo has bragging rights in my family. With her driving on a couple of trips she got 16.7 MPG. Keeping in the primaries at a steady 75-80 in my 76CdV our trips from San Antonio to corpus christe (TX) results in 15-16 MPG.
The torque multiplication of the early Hydromatics helps getting the early Cad's moving with Thor reduced HP, thus making decent mileage possible. Again mileage is greatly determined by your right foot
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Jay Friedman

My '49 has a manual transmission but a 3.36 ratio differential normally installed in '49s with Hydramatic.  Even though the motor is in fine tune, it only gets 16 or 17 mpg at highway speeds. 
1949 Cadillac 6107 Club Coupe
1932 Ford V8 Phaeton (restored, not a rod).  Sold
Decatur, Georgia
CLC # 3210, since 1984
"If it won't work, get a bigger hammer."

billyoung

I think my 1968 is probably getting 6 to 12 MPG.
Age 68, Living in Gods waiting room ( Florida ) Owned over 40 Old Cadillac's from 1955's to 1990 Brougham's. Currently own a 1968 Cadillac DeVille Convertible and a 1992 Cadillac 5.7 Brougham.

Bwt

My 61 gets 8. Low mileage original car. Doesn't burn oil, minimal blow by. Timing, etc adjusted to specs. Vac advance is operational. Just does not do any better, however that is typically just 7-10 mile trips.

Delo427

On a 200 mile round trip of mainly highway, my 68 got 11, which they said 12 when new, so that's pretty good!

64\/54Cadillacking

That's actually pretty damn good Clay. Some modern trucks with similar size engines and horsepower don't even average that much MPG.

And your limo must weigh close to 6,000lbs!!

I don't think people realize when our engines are properly tuned, and if you can find ethanol free gas, your gas mileage is equivalent to what modern turbo 4 and 6 cylinder engines are getting. Sure the newer turbo car will have more power than some of our old Cads, but they have to work extra hard to move heavy SUV's and trucks that they won't last hundreds of thousands of miles like an old school natural aspirated V8 can.
Currently Rides:
1964 Sedan Deville
1954 Cadillac Fleetwood 60 Special
1979 Lincoln Mark V Cartier Designer Series
2007 Lexus LS 460L (extended wheelbase edition)

Previous Rides:
1987 Brougham D' Elegance
1994 Fleetwood Bro
1972 Sedan Deville
1968 Coupe Deville
1961 Lincoln Continental
1993 Lincoln Town Car Signature Series
1978 Lincoln Continental ( R.I.P.) 1978-2024 😞

Cape Cod Fleetwood

#DriveItLikeYouStoleIt
There are 2 kinds of cars in the world, Cadillac and everything else....

The Present -1970 Fleetwood Brougham

The Past -
1996 Deville Concours
1987 Sedan De Ville "Commonwealth Edition"
1981 Coupe De Ville (8-6-4)
1976 Sedan De Ville
1975 Sedan De Ville

The Daily Driver and work slave -
2008 GMC Acadia SLT *options/all

"Cadillac Kid" Greg Surfas 15364

I've got my 73 "hot rod" for that. 6.5 MPG of $18.00 per gallon VP-MS109 to get me to the track then 12 second 110 MPH quarter miles then back home. Gets all my need for speed satiated. Then back to my sedate 75 and 76 CdVs and NO TICKETS. Drive it like you stole it gets expensive
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Lexi

#9
Quote from: Cadillac Kid on May 13, 2023, 03:44:15 PMThe torque multiplication of the early Hydromatics helps getting the early Cad's moving with Thor reduced HP, thus making decent mileage possible. Again mileage is greatly determined by your right foot
Greg Surfas

Interesting comments. I am particularly fascinated by the torque multiplication notation and what this actually means. Something new to me. Reducing it to a "3 Stooges" level (me), what does that mean Greg? In the past I have been told that these old hydramatics actually gobbled up horsepower, at least at low speed. My car I believe has the same rear end gear ratio as Jay's '49., (3.36). If I understand that correctly, wouldn't that adversely affect mileage at highway speeds? Guess I got lucky the other day with mileage. No tail wind, just clear "sailing". Think the Limo is near 5,500 lbs. or a touch less with tools in the trunk. Clay/Lexi

"Cadillac Kid" Greg Surfas 15364

The lower (higher numerical) gear ratios in first and second gear get the car moving with less throttle thus less fuel consumed
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Jay Friedman

Quote from: Lexi on May 14, 2023, 02:14:30 PM..... My car I believe has the same rear end gear ratio as Jay's '49., (3.36). If I understand that correctly, wouldn't that adversely affect mileage at highway speeds? Guess I got lucky the other day with mileage. No tail wind, just clear "sailing". Think the Limo is near 5,500 lbs. or a touch less with tools in the trunk. Clay/Lexi

'49s with manual transmissions usually have a 3.77 ratio differential. With one of those, I think my mpg would be even worse.
1949 Cadillac 6107 Club Coupe
1932 Ford V8 Phaeton (restored, not a rod).  Sold
Decatur, Georgia
CLC # 3210, since 1984
"If it won't work, get a bigger hammer."

Cape Cod Fleetwood

Quote from: "Cadillac Kid" Greg Surfas 15364 on May 14, 2023, 02:10:34 PMI've got my 73 "hot rod" for that. 6.5 MPG of $18.00 per gallon VP-MS109 to get me to the track then 12 second 110 MPH quarter miles then back home. Gets all my need for speed satiated. Then back to my sedate 75 and 76 CdVs and NO TICKETS. Drive it like you stole it gets expensive
Greg Surfas

Phttt.... rookie... I've been stopped at least a half dozen times with The Ark, not even a warning. Just a friendly
chat.  8)
There are 2 kinds of cars in the world, Cadillac and everything else....

The Present -1970 Fleetwood Brougham

The Past -
1996 Deville Concours
1987 Sedan De Ville "Commonwealth Edition"
1981 Coupe De Ville (8-6-4)
1976 Sedan De Ville
1975 Sedan De Ville

The Daily Driver and work slave -
2008 GMC Acadia SLT *options/all

"Cadillac Kid" Greg Surfas 15364

What can I say?
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Eric DeVirgilis CLC# 8621

#14
According to one online source, curb weight of the 1953 Series 75 Sedan is 4810 lbs; 4863 lbs for Imperial Sedan (presumably w/o air conditioning). Walter McCall puts it at 4,900 lbs and Richard Langworth states up to 4,850 lbs in the Illustrated Cadillac Buyer's Guide.

When Motor Trend tested a 1953 Series 62 Sedan (4,225 lbs) fuel economy was reported as follows:

30 mph: 24.2
45 mph: 22.1
60 mph: 18.6
75 mph: 14.5

M/T also noted that fuel economy of the '53 Cadillac was improved 30% over the '52 model.
A Cadillac Motorcar is a Possession for which there is no Acceptable Substitute

Cape Cod Fleetwood

Quote from: StevenTuck on May 15, 2023, 07:32:38 AMChat... Really? I have owned my car 24 years now and owned two others during that time. I have NEVER been stopped for a chat. I guess Laurie's hyperbole rolls on.

3 reasons for your lack of interaction with your areas Finest:
1) You can't/don't drive your cars fast.
2) You don't have the police presence we have around here.
3) Your cars aren't good looking enough to draw their attention in the first place.
Not hyperbole... Not a joke...

My favorite so far, stopped on Route 6 West by the State's Finest:
Cop: Ma'am do you have any idea how fast you were going?
Me: Sir, I'm guessing but probably 80.
Cop: Ma'am 82 MPH
Me: Sir, not bad for a 51 year old car eh?
Cop: Not bad at all!
There are 2 kinds of cars in the world, Cadillac and everything else....

The Present -1970 Fleetwood Brougham

The Past -
1996 Deville Concours
1987 Sedan De Ville "Commonwealth Edition"
1981 Coupe De Ville (8-6-4)
1976 Sedan De Ville
1975 Sedan De Ville

The Daily Driver and work slave -
2008 GMC Acadia SLT *options/all

Lexi

Quote from: Eric DeVirgilis CLC# 8621 on May 15, 2023, 08:42:13 AMAccording to one online source, curb weight of the 1953 Series 75 Sedan is 4810 lbs; 4863 lbs for Imperial Sedan (presumably w/o air conditioning). Walter McCall puts it at 4,900 lbs and Richard Langworth states up to 4,850 lbs in the Illustrated Cadillac Buyer's Guide.

When Motor Trend tested a 1953 Series 62 Sedan (4,225 lbs) fuel economy was reported as follows:

30 mph: 24.2
45 mph: 22.1
60 mph: 18.6
75 mph: 14.5

M/T also noted that fuel economy of the '53 Cadillac was improved 30% over the '52 model.

Those mileage specs are interesting. A little higher than I would have guessed. Assuming for a base car. I imagine those specs would change as the decade rolled on. For my 1956 Imperial Limo I got 2 weight references; one at 5050 and another at 5220 lbs,(sic), but they were stated as for the 8 Passenger Sedan, (non-Limo model-no division window). So at this point I am still not certain what my car's curb weight was. I would agree that the specs you provided for model year 1953 are probably minus AC, (if included would add a hefty chunk of weight). On my '56 that evap unit must weigh around 75 lbs and the compressor 50ish? Add up all the other related AC components and you might have 150 - 200lbs. Mine is fully loaded even with sabre rims and of course the division window assembly. As I said toss in the tool kit weight in the trunk and has got to be around 5,500 rolling down the road. Will dig through my literature to see if I have any curb weight specs somewhere. Should check my car's weight one day on some weigh scales. Clay/Lexi

Note: For those interested in this mileage thing and my road test results noted above, my car is equipped with a rebuilt, stock Rochester carburetor. Everything is stock except for the Pertronix ignition installed.

Eric DeVirgilis CLC# 8621

Quote from: Lexi on May 15, 2023, 11:27:29 AMOn my '56 that evap unit must weigh around 75 lbs and the compressor 50ish? Add up all the other related AC components and you might have 150 - 200lbs.

Don't forget about the condenser, extra fans and ductwork in a Series 75, 200 lbs may be conservative.

And all that is before you turn the thing on which will make it feel as if you instantly hooked up a 3,000 lb trailer to the car.   :o
A Cadillac Motorcar is a Possession for which there is no Acceptable Substitute

Lexi

Quote from: Eric DeVirgilis CLC# 8621 on May 15, 2023, 02:25:32 PMDon't forget about the condenser, extra fans and ductwork in a Series 75, 200 lbs may be conservative.

And all that is before you turn the thing on which will make it feel as if you instantly hooked up a 3,000 lb trailer to the car.   :o

Yes, hence why I said "all the other related AC components", right down to the exterior metal beetle shaped air scoops plus the weight of the freon. The ducts on the Series 75 are huge 6 or 7 foot long pieces. then you got the aircraft like 2 rows of chrome metal ducts along the headliner. Then under the dash the metal AC control panel. My back hurts just thinking of the job it is to lift that compressor off of its cast iron bracket and moorings. Oops, then there are the triple grooved AC pulleys, extra belt... The list continues to grow. So I agree, 200 lbs may be conservative. Still can't find any curb weight specs for my car. Everything else, but, so far. Clay/Lexi

Eric DeVirgilis CLC# 8621

Quote from: Lexi on May 15, 2023, 02:34:45 PMStill can't find any curb weight specs for my car.

After going through the brochure, owner's manual and the 1956 Data Book - all 300 pages of it - neither can I. The spaces for "curb weight" are left blank on official factory documents while directing the owner to check with the dealer's service department. It seems that curb weights were a jealously guarded secret at Cadillac in those days. Astonishing. 
A Cadillac Motorcar is a Possession for which there is no Acceptable Substitute