: convertible? 68 deville?



diz
02-20-05, 02:28 PM
hi all. this is my first post on the cadillac forums.

i'm not much of a car guy. i try to do as much maintenance on my vehicle as possible, but i spent my teenage years learning about computers.

anyway, i want a convertible. and i want a beautifully classic machine. something that i can work on. something that i can learn from. i've had my eyes on a cadillac for a while, but just haven't taken the plunge. from what i've read, the 472 in the 68 deville lasts forever, which is amazing to me. i've read some posts from people that have said they've seen 200 and 300 thousand miles on the 472 and only minimal cylinder wear.

my major concern is gas mileage. i dislike the american reliance on oil, and i don't have pockets deep enough to feed a machine that gets 10 miles to the gallon. i've read that a rebuilt carb and well-tuned timing can get you 15-20 mpg with the 472, is this true?

i like the looks (especially the stacked lights) of the 68 deville, but, like i said, i'm not a car guru. what other options should i consider checking out in a convertible? is the deville the only convertible cadillac model?

anyway, thanks for any comments. i hope to own one soon :)

-mike

davesdeville
02-20-05, 03:39 PM
In 68-76, all Caddys (except the new 76 Seville) used 472s and 500s. Great engines, but you'll be disappointed if you think you'll see 20 mpg unless you're cruising 60 on the highway. With a perfectly tuned car, 12 in the city is reasonable. A drop top was optional on 68-70 Coupe Devilles and 71-76 Eldorados. 75-76 Eldos had a fuel injection option which could be worth maybe 1mpg..

CoupeDevilleRob
02-20-05, 03:44 PM
If you're looking for gas mileage don't look at a 472 Caddy. I don't know how often you'd be driving it, but assuming it's a weekend fun car the damage done but the awful mileage shouldn't be too bad. If it's gonna be a daily driver though, look for a second job.

diz
02-20-05, 04:07 PM
hrm. what about the 429? is it only marginally better?

any issues with dropping a 429 in a '68 body?

if it were to be my weekend fun car (which i'd love it to be), i'd have to buy it cheap and pretty much restore it myself. not that it wouldn't be a great way to learn, but i don't neccessarily have the time or the money for that. having it as my primary vehicle was the reason i asked about fuel efficiency.

seems i'm stuck with a rather difficult choice. i pay through the nose in insurance on my current car (2001 nissan maxima SE 5 spd - $250/mo). i wonder if i could save enough per month on insurance to warrant paying it back out in gas.

gas usage is a separate philosophical/political decision i'd have to justify, though...

-mike

Fred Fachman
02-20-05, 06:54 PM
The 429 actually makes worse mileage than the 472/500. Honestly, if you are really concerned about mileage, Cadillacs produced in the 60's and 70's should be avoided. They make great weekend cruisers, but as an everyday driver can be very costly to operate. Don't let me discourage you from owning a classic Cadillac, just don't plan on it as a daily driver. 1982 and up make better mileage,parts are easier to find and are less expensive to buy. When you get a little more affluent, go get that '68 and enjoy it without worrying how much fuel it burns.

davesdeville
02-21-05, 03:34 AM
If you can get classic car insurance it might save you enough to cover gas. I picked up a 95 ETC for gas mileage purposes but since I just got it a month ago I'm still enjoying its 300hp at the cost of 14mpg... you might consider picking up something like an older Corsica or something that makes better mileage as a daily.

cadillacmike68
02-22-05, 01:06 PM
Well obviously, I would reccommend a 1968 DeVille Convertible! Actually 1968-70 DeVille Convertibles or 1971-72 Eldorado Convs are your best bet. The DeVilles are almost devoid of smog control bullsh!t while the 2 Eldos are the least encumbered smog era cars. 73-76 are the biggest gas hogs (remember your history sonnie?).

From 1971 on the compression ratio went from 10.0:1 (1970, 1968-69 had 10.5:1) to like 8:1, with a corresponding power drop!:eek:

Good luck, pick a copy of Hemmings motor news, you'l see convertibles from all these years.

cadillacmike68
02-22-05, 01:15 PM
hrm. what about the 429? is it only marginally better?

any issues with dropping a 429 in a '68 body?

if it were to be my weekend fun car (which i'd love it to be), i'd have to buy it cheap and pretty much restore it myself. not that it wouldn't be a great way to learn, but i don't neccessarily have the time or the money for that. having it as my primary vehicle was the reason i asked about fuel efficiency.

seems i'm stuck with a rather difficult choice. i pay through the nose in insurance on my current car (2001 nissan maxima SE 5 spd - $250/mo). i wonder if i could save enough per month on insurance to warrant paying it back out in gas.

gas usage is a separate philosophical/political decision i'd have to justify, though...

-mike

The 429 will fit, but don't bother, the engine is not as good or even as efficient.

A 425 (from 1977-80) might be a bit better.

"The price of gas doesn't matter if your job pays enough" :coolgleam


How did your insurance rate go to $250.00 / month for ONE car. Mine is like 175/ month for FOUR cars. That seems to be a bigger problem than the current price of gas.

Don't worry about political misgivings, just buy gas from Hess or one of the other companies that do no import middle eastern oil. There's a list on the web somewhere. Hess is one of the good guys, ZERO percent imported oil.

You can get restorable examples pretty cheaply (If you think $3,000.00 - $5,000.00 is cheap). ;)

cadillacmike68
02-22-05, 01:19 PM
Gotta disagree with Fred.

While the V8-6-4 was OK (It was a 6.0L / 368CI), it lasted only 1 year then the infamous 4.1L aluminum heads iron block disaster came on the scene, better mileage, horrible longevity, and NO CONVERTIBLES in this time period.

My 1968 got 10-12 MPG before cylinder # 7 went bad. I expect it will get 10-20 MPG depending on my driving habits (lead foot) after rebuild.

cadillacmike68
02-22-05, 01:20 PM
If you can get classic car insurance it might save you enough to cover gas. I picked up a 95 ETC for gas mileage purposes but since I just got it a month ago I'm still enjoying its 300hp at the cost of 14mpg... you might consider picking up something like an older Corsica or something that makes better mileage as a daily.

My 2000 ElDorado ESC Convertible (275HP) gets 20-22mpg average and I have a lead foot. I got 24MPG on an 80MPH trip From Tampa to Miami in Dec. That was up to the point where I turned east into a 50mph headwind that lowered my average MPG from 24 to 21 in 1 hour.:eek:

davesdeville
02-22-05, 06:36 PM
I was getting about 30 doing 65 back east and 22-24 doing 85 on the way through OK, TX, and NM. It was about 12 at 150mph.. But in the city it's 14 when I drive with a lead foot, your lead foot must actually be aluminum or titanium in disguise. I'm getting better though todays average was 19.

DaveSmed
02-22-05, 10:34 PM
As it has been mentioned, for as bad as these cars are on fuel in the city (which isn't TOO bad, unless your driving tends to be on the agressive side) they do suprisingly well on the highway, due to the gearing, and trans design. (despite lack of overdrive) The transmissions tend to keep the rpms low, and try to upshift whenever possible to maximize economy. The low rpm part is also benifical since these engines make most of there power down low. As far as hard numbers, I don't have enough highway specific data to be of much help. But for what its worth, I think your dead on when it comes to styling... :thumbsup:

Fleet
02-23-05, 01:56 AM
Well obviously, I would reccommend a 1968 DeVille Convertible! Actually 1968-70 DeVille Convertibles or 1971-72 Eldorado Convs are your best bet. The DeVilles are almost devoid of smog control bullsh!t while the 2 Eldos are the least encumbered smog era cars. 73-76 are the biggest gas hogs (remember your history sonnie?).

From 1971 on the compression ratio went from 10.0:1 (1970, 1968-69 had 10.5:1) to like 8:1, with a corresponding power drop!:eek:

You would recommend a '68 DVC? I wonder why? :D

I was wondering, since I own a '69 Fleetwood Brougham, what changes in smog control equipment was done from '68 to '69?
I agree... '74 was probably the worst year for fuel mileage because that was the last year before the catalytic converter and they had to ruin mileage in order to better smog output. '75 and '76 models were better for fuel mileage than the '73-'74.

Yeah, too bad the compression dropped from 10.0 in '70 to 8.5 for '71-'74, 8.25 in '74, and back up to 8.5 for '75-'76.

cadillacmike68
02-23-05, 04:13 PM
Emissions changes from 68-69 and 69-70

68-69:
1. I think the carb model changed (but that would be insignificant)
2. The radiator went to a closed loop coolant recovery system (helped prevent overheating, negligable emissions effect there too).

69-70
1. Ludicrous A.I.R. system deleted (the air pimp disaster), one less fan belt in the bargin.
2. A thermostatic tube from the air cleaner to the exhaust manifold to get warmer air into the carb quicker.
3. If carb didn't change from 68-89 it changed here.
4. Compression ratio dropped from 10.5:0 to 10.0:1 with NO LOSS of power hmmmmm.....
5. Something called transmission controlled spark (TCS) whatever that was first used.

cadillacmike68
02-23-05, 04:25 PM
You would recommend a '68 DVC? I wonder why? :D

Because of the vent windows, of course :p

I was wondering, since I own a '69 Fleetwood Brougham, what changes in smog control equipment was done from '68 to '69?

A 68, 69 or 70 Fleetwood Brougham is on my list too...:) NICE cars. I had a black 1970 Fleetwood brougham while in college in Mass, but it rusted away. :disappoin