1962 CDV gas mileage on a long trip...

[Edward Kenny]

Earlier today I had a conversation about taking a trip from New Jersey to Chicago and back in my '62 CDV. I then did a gas mileage calculation that seemed too good to be true.

Am I correct if I say that most of us Cadillac owners of cars built between 1946 and 1964 most likely get around 15 miles per gallon on the highway (interstate)? That's about what my '62 390 gets.  Google Maps tells me that it is 764 miles to Chicago from my house. If so, then I calculate that a little more than 2 full tanks of gas (about 55 gallons: I have a 26 gallon tank in my car) would get me to Chicago. If I go by the national average cost of a gallon of gasoline ($3.88 today for premium), then it would cost me $213.40 for gas for a trip to Chicago one way. This seems WAY TOO GOOD to be true.

My question is: has anyone made a comparable trip in their postwar Cadillac and can therefore tell me the REAL cost of gas of such a trip?

[INTMD8]

Yes your math is correct.  Trip distance/mpg x cost per gallon

You would spend around $200 in fuel each way.

Last trip I took in my 59 returned 14.4 mpg calculated off the stock odometer at an indicated 85-90mph.

[Coupe Deville]

Jim, just out of curiosity. What carb are you running? AFB or Rochester?

[INTMD8]

Jim, just out of curiosity. What carb are you running? AFB or Rochester?

AFB.  Original to the car fwiw.

[Walter Youshock]

Going to the 2002 national in Detroit,  I hit 20.1 through Ohio in my '57.  No air car but I was stunned.   Nice flat roads with no hills and the car just floated along at about 60.  Had I pushed it, I would have used a lot more gas.  I think overall, I got around 16 or 17.

Even on the way back to Scranton on the mountains, I never felt the car downshift to third. 

[The Tassie Devil(le)]

When I drove around USA and Canada in 2002 (in a 1989 Thunderbird as I couldn't find a '72 Eldorado to buy), I found that the worst fuel economy I got was from the Southern States.   I drove 14,750 miles in just under 4 Months, and kept good records, including photos of every purchase.

But, in 2008, when I purchased my '72 Eldorado Convertible, and drove that 4,900 miles in North-East USA and Canada, I was getting 16.5 to 17 MPG.

Mileage depends on one thing.   The big right foot.

Bruce.

[Coupe Deville]

Mileage depends on one thing.   The big right foot.

That's the truth. I just recently got my drivers liscence and now I know why my 72 gets such better mileage......because my dads not driving.

[Dan LeBlanc]

Wow.  My 61 Fleetwood is giving me 12.4-12.7 mpg.  Mind you we are in somewhat hilly terrain here, so that doesn't help.

Best I've seen out of it was 14.4.

[Eric DeVirgilis CLC# 8621]

I get a chuckle whenever someone inquires about fuel mileage of a classic car. I always my answer is a standard, "I have no idea..."

Does it really matter on a <2,000 mile/year driven car?

In any case, most classic cars get no worse mileage than a lot or modern mega-gigantic SUVs & pickups - whose owners apparently have little concern about the issue -  many of which are driven daily. Some of them are diesel which costs even more than super.

[Walter Youshock]

Many years ago, I was filling the '57 at the local gas station.   A woman asked, rather snottily,   "what kind of mileage do you get on THAT thing?"  I replied: "lady, when you own a car like this, you don't give a rat's behind.  It's about the pride of ownership,  not the mpg."

[Eric DeVirgilis CLC# 8621]

Don't get me started on ethanol...

[INTMD8]

Does it really matter on a <2,000 mile/year driven car?

No, I would drive it either way but I find the data interesting. Plus I drive mine more than that 

[Dave Ventresca]

FWIW, my 53 CDV got an honest 19 mpg on flat highway driving , but the 53 eldo gets a little less due to extra weight. (lead mobile). but I agree, who cares? Dave

[cadillacmike68]

I have an original Consumer Reports on the 1968 Sedan DeVille (the whole magazine, not just the car review reprint) It also has that year's new car review.

they have their test results on it including MPG. I'll go get it and post the #s here.

They also had some nice things to say about the car.  Amazing for CR...  But it was back in 1968, before their severe anti-American-car bias took hold.

Here are their MPG results:

Steady speeds:
30 MPH:  18.5
40 MPH:  17.5
50 MPH:  17.0
60 MPH:  15.0
70 MPH:  13.5

Expected normal use: 7 to 15 MPG

My car gets 8-13 MPG, but I routinely have it up over 70, and city driving just wipes out the MPG

If there was anything CR was good at, it was figuring out MPG. 

[Michael J. Cascio]

On my '62 i thought I was getting between 16-18mpg. That was until I discovered the speedometer was clocking miles and indicating speed about 16% greater than actual. After recalculating, my highway trips average inbetween 13-14.5 at 70-75mph with the a/c on. Dont expect any better, reviews from the period showed an overall average of 8-12mpg.

[signart]

FWIW, my 53 CDV got an honest 19 mpg on flat highway driving , but the 53 eldo gets a little less due to extra weight. (lead mobile). but I agree, who cares? Dave

The only long trip I kept track of with my '53 coupe, I too logged 19 mpg on a 1000 mi. round trip down I-75 Georgia. I kept up with traffic for the most part and it liked cruising at 70-75. I discovered after returning, it was in bad need of plug wires, in particular the coil wire which was severely corroded.