Can '80s 'muscle' be ecomodded?
 

Going to try to improve on the improbable.
1987 Oldsmobile Cutlass one of the last of RWD body on frame midsize V8 coupes.
140 odd horsepower of smogged to death goodness pushing ~3500lbs
It may be a hopeless challenge but someones got to try :p

The good.
Fairly sleek body design, can easily reach triple digit speeds.
The bad.
Whoever thought an electronic carbuerator was a good idea needs their head examined.
The ugly.
Can you believe GM stuck 2.14:1 final drives in these cars. 0-60 with a sun dial, but cruising with traffic and the tach staying well below 2Krpm always gives me a fuzzy feeling.

Original EPA was 17/23, revised is 15/21. Is 18/25 too far off, maybe 20/27.
Lets trim some weight off this piggy and see what she can do.

Trimming weight will help most in stop-and-go city driving. Cutting aerodynamic drag will help most for highway cruising. Maxxing-out the tire inflation will help both.

Why bother? Sell the thing (or give it away) and get a small FE frindly car. Both cheaper and better for the environment!

Yes......sell it! (jezzzz........)

You sell it to a boy from the hood.
He wants 'dubs'
He gets finasncing at the local rim shop and pays $3000 for 22" rims and tires. (ps europe....waste of material!!!!.........'sell it'..........)
he also gets teribble mileage.
The the car is repo'd because he cant make payments on the rims......
(should I go on...........)
you buy another car.........more waste.

welcome MAD MIKE!

What about a desiel replacement at some point?
love the rear ratio!

My 66 mustang had a straight six 200 ci and a 2.89 rear ration......loved freeway driving!

My opinion is swap in an obd2 engine and ecu if possible, the advanced computer controls will make a big difference.

Lax swap!!! For economy I vote for a junkyard 4.8 or 5.3 backed by a 6 speed and decent rear gear. Maybe 3.08 or 3.20's? Eliminate all smog stuff you can and have it tuned for economy at cruise and power when you need it.

Or is reusing the original engine eliminate all the smog stuff and add a better flowing intake/carb with better flowing exhaust. Manual trans conversion.

It's simple, it's heavy and not aero dynamic... so you might be able to do better with some mods but even if you swap a diesel or even electric drive you're still using double the energy a cheap small car will use

First off welcome to the forum. Second don't sell it... Especially if there isn't anything wrong with it! The first thing you should do is make sure your vehicle is tuned up and happy. Air filter, plugs, wires, dizzy cap, rotor, carb adjustments, etc...

If you haven't already started doing so start keeping detailed records of your fill ups and mileage. You can calculate MPG and get a ballpark average. The first mod you should think about is to do a "driver mod". See the 100+ hypermiling tips we have here..100+ Hypermiling tips

Since you have a carb try a vacuum gauge and note what readings you get around town, on hills, cruising and on the expressway. A vacuum gauge isn't perfect but it will get you an idea of how hard the engine is working. You want to balance RPM, gear and engine load to get the best efficiency.

The physical mods should wait until you get some baseline numbers. It isn't good to start going nuts and not really know if what you did made an improvement or maybe made your fuel economy worse.

+1 to what Razor02097 said.

Your car is lighter than my truck and has less frontal area. You have a less efficient engine and (I'm guessing) an automatic transmission, but that just gives you more opportunity for improvement.

Good records + persistence is the key.