hi, i'm new to this board and cadillacs as well. i'm a newbie when it comes to cars i've attempted to learn a few things here and there but i'm still nonetheless clueless. i've been driving an '88 cadillac brougham and i've calculated my gas mileage to be about 10 mph on regular city driving. i'm proof positive that i can be doing a lot better than that. what are the first steps i should take to improve my gas mileage?

hi, i'm new to this board and cadillacs as well. i'm a newbie when it comes to cars i've attempted to learn a few things here and there but i'm still nonetheless clueless. i've been driving an '88 cadillac brougham and i've calculated my gas mileage to be about 10 mph on regular city driving. i'm proof positive that i can be doing a lot better than that. what are the first steps i should take to improve my gas mileage?
Hey welcome to the board deadatdusk. How long have you had the car and how has the service history been? Has the gas milage been screwed up for a while or has the car been that way for a while? If you recently got the car, it would be best to do a full tune-up (spark plugs, wires, dist. cap, rotor, set timming and idle speed, change out all of your filters-air, fuel, pcv valve, crank vent. filter, etc.). I would also change all fluids on the car just because you dont know when the owner befor you did all of that stuff. Post some more info on the cad and the other members here will offer you even more help then myself as I am an amature mechanic.

It's been sitting in my driveway for about five years now and was previously owned by another family member. Whoever owned the car before that time I am not quite sure of. However, the most recent previous owner is really oblivious to the fact that the gas mileage is poor I believe fluids and such had been checked every 4-6 months. The car was not often driven, until I began using it daily. I have been driving this car since August of 2003 I noticed I had very poor gas mileage, as well as a gassy smell inside and outside the car. I took it into a repair shop and there was supposedly a leak in the fuel system....lets see 09/19/03 a new fuel pump was installed, drained and replaced motor oil. (As of 2001 the car was at about 87,000 miles...now it is well over 105,000 ..if this info is useful...). Other than that there is no other evidence of any work done that's been fuel related (that I can find). There was a problem with the steering column as well as the f-left window motor. But nothing else fuel related. After getting the car back from the shop it seemed to be in a much better condition. However, thats how it seemed. I payed little attention to the problem which still seemed to exist, I just sucked it up and shelled out for the extra gas expense. I feel it's really gotten to be a problem as of lately. Especially now that I've been making much longer commutes around town.

update:


i recently spoke to a mechanic regarding whether or not a faulty o2 sensor could be causing this problem, he said that it is definately the carb that has a problem and that the o2 sensor has little to do with anything because of ... some reason. then he went on to say that this problem with a newer fuel injected car would have a better likelyhood of having a faulty o2 sensor.

hmmm?

Hmmm... :hmm:

I did this and it improved my mileage. I bought STP Carb/FI cleaner that you pour into the gas tank and my Brougham has more power, goes faster, and hasn't been using as much gas. What you do is pick it up for like $1.60 and pour it in your tank with no less than 21 gallons. I would suggest next time you fill up pour it in the tank before the attendant fills your tank so you're sure to have at least 21 gal. It cleans out the carb really well and the entire fuel system. Good luck, gas is going down anyway so regardless you'll see an improvement in your trips to the gas station.

thanks for the advice. if anyone else knows how to fix these plz let me know

thanks for the advice. if anyone else knows how to fix these plz let me know
What I would do since the car was sitting for that long of a period without any driving, I would change all fluids (as you know engine oil should be changed 3mo/3K which ever comes first). Next I would look into getting a new carb. and doing a full tune-up and if you got any shot sensors (i.e. o2 sensor) I would replace them at that time and you should get better gas milage and the car will run much better. I get around 16-18 MPG in my '85 Fleetwood Brougham while driving 40% hwy and 60% street. Good luck with your car deadatdusk

hmm. yea i was hoping to avoid purchasing a new carb. perhaps i should just look into buying a new caddy all together.

hmm. yea i was hoping to avoid purchasing a new carb. perhaps i should just look into buying a new caddy all together.

Why? It shouldn't be too hard to find a rebuilt one or to get yours rebuilt and it's something that's going to be needed eventually on any car with one. Did he say what was wrong with it?

It shouldn't be too hard to rebuild the carb yourself...I haven't done one in years (since everything in the last decade or so has been fuel injection), but if I recall it didn't take more then a couple hours to rebuild one in the "good old days"....The rebuild kits go for around $30.00 at any local autoparts store...I would also assume that any local garage would rebuild one for $150 or less...In the end if it would improve your gas mileage by 3-4mpg it would pay for itself in no time....especially at $2.00 a gallon....lol
I plan on doing mine in the next few weeks.....Have an 87 brougham that was getting 11mpg when I bought it.....After a tune up it got 13mpg (mostly highway driving....But then I drive 80mph...lol)...So the carb is the next step for me. Have to remember that when things get almost 20 years old they tend to wear out and not work like they should....

Dan

I recently took the car for a smog test and it passed with nearly perfect readings in all aspects. What does potential problems might this rule out and how does it relate to the MPG. I spoke to yet another mechanic this one a bit more wise with years, he suggested a possible leak might be the cause of my problems. He was not too suggestive of the carb rebuild idea (though I have not ruled it out). I'll most likely have it inspected yet I'm still curious as to receive feedback from members on th is board.

A new 02 will help. I had to put a new 02 into my Buick electra(same size as an 84 brougham or bigger) and it helped with me gas mileage.

A new carb will help also. Just don't have a heavy foot, and also don't do any Jack rabbit starts and it should help also.

i had a supposed leak fixed on the fuel line going into the carb, i took a highway trip and got 16 mpg there and back. after that it has all been city driving and i've still been at about 8-10 mpg. i'm wondering why?

Try a few tricks I do to improve my mileage. Don't use your accelerator on downgrades and only for uphill, use highways instead of backroads, and every now and then put premium in the tank. My 89 Brougham lasts longer between fill ups than my 99 Malibu! I think the 25 gal. tank plays an important factor here.

Dead, have you checked for vacuum leaks? Those things will kill your mileage for sure. A bad PCV will do it sometimes. Also consider cat/ exhaust restrictions. Dope's car gets good mileage 'cause it's too damn nice to drive fast where people can't get a good look at it. :cool:

Dope's car gets good mileage 'cause it's too damn nice to drive fast where people can't get a good look at it. :cool:
Well what can I say, the man's a smart one. :bighead: