I have a 80 Chrysler LeBaron Medallion 2dr with 60k original miles that I would like to try to get the CITY MPG better. It is a 318/904/2bbl car
with a 2.4 rear gear. I do not want to gut the car or change its overall appearance just to try to improve CITY MPG. Car's CITY MPG is 17 and I would like to improve it on a budget. I have followed HotRodDaves thread and it put me on the road to what I think I need. I plan at present to change intake to Performer or sp2p with a 800 t/quad..Iknow I will have to change air cleaner and kickdown/acc linkage. Down the road I will go to headers/exhaust and as a last resort change to A833 OD trans. and rear gear. Again this is on a budget and to improve CITY MPG. THANKS

A gear change would definitely help. The 2.45's are great on the highway but suck around town. I think 3.21's would be the ticket. Problem is you'll have to swap the rear end as I believe 8.25 housings that had 2.27/2.45 gears won't accept the 2.71 and lower gears.

Station wagons usually had 3.21's so if you could find a Lebaron/Aspen or Volare wagon that would work.

There are always people swapping out 8-1/4" F- and M-body rearends in favor of 8-3/4" rears, and higher gears would be a great first step.

With a miserly 4-bbl carb and the SP2P economy intake, I doubt you'll see more than a 3mpg increase. The 2.45 rear gears are horrible for low speed use, no matter what the engine combo is.

Your stock intake exh-heat-crossover is probably plugged(and the cyl head too) and is hurting MPG big-time.

An SP2P intake and a small TQ will help MPG a bunch.

If you're getting 17mpg CITY I think you should count your blessings and move on. I don't think any 318 car is really going to do any better in the city than that. And any mods you do aren't likely to repay themselves in fuel savings.

318's are all over the map. I have a Bud that has a couple of M body 4 doors ...and he says he gets over 20(city - stop and go) ... up to 28 on the freeway.

IF his intake crossover is plugged .. the choke is on way WAY too much ..and the MPG will take-a-dump.

Also ...what is city MPG ? .. stop-and-go low speed ? ..OR to-the-grocery-store and then back ...without really letting the engine get up to proper operating temp.

I'd kill for 17 in town but as said I'd go to a 3.21

Yep, punt that leanburn atrocity.

How do you define in-town ?

Before you do anything, calculate your investment versus savings.

Let's say you drive 5,000 miles/year and let's use 17 miles/gallon as the base fuel economy number. That means you'll use 294 gallons/year. Now bump that mileage figure up to 21 (which I think is very optimistic) and you'll only use 238 gallons/year. At a cost of $2.75/gallon (you ARE putting premium in it RIGHT? ), you'll spend $154.00 less in fuel costs via the extra 4 mpg.

I say save your pennies for fun mods or buy a car with better mpg.

It's not really budget friendly but I would switch out the open chamber heads for #302 closed chambers, swap on a performer manifold with a holley 2 barrel projection, add a MSD 6A and a recurved dist and build a 2.25" Y pipe off the stock manifolds run to a single 3" exhaust with a magnaflow or dynomax ultraflo.

A 3.21 will help if it's all city driving, if it's a 50/50 split city/hwy go with 2.94's.

A fun mod would be a o/d 833 and some 3.55 gears. Would make for a low highway rpm and the high ratio 1st would give decent takeoff ratio at launch.

I have to dispute that going to a numerically higher differential ratio will help city driving MPG.

Where the MPG might be hurt is if you are impatient and put your foot down on the pedal, which triggers both the accelerator pump and takes you into the factory fuel enrichment mixture region.
This can easily hurt city MPG by 30% or more
but is not caused by the differential,
but by the driver.

Keep a light gentle foot and the low numerical ratio with help you.... better MPG was why Chrysler put it there years ago, both for
highway MPG {that requires almost no driver skill}
and for city MPG improvement {that improper driving technique can totally destroy}

For a second opinion ask a 'Hypermiler' that has been competing and has placed in the top 3 of any such event.

If the original lean burn system seems intact, consider buying or borrowing a portable wide range oxygen sensor system
and try to make sure the air to fuel ratio is where Chrysler intended it to be,
along with ignition timing that will seem
'way too advanced'
compared to the numbers you regularly hear.

However, the easiest way to get better city MPG
is to change tires
to one of the
'low rolling resistance' designs.
Here's a link to an (old) listing:

http://ecomodder.com/forum/showthread.ph...report-520.html

There is a also a report from the USA's 'non-partisan'
National Academy of Sciences
about tires that came out a few years ago:

http://www.thefreelibrary.com/Tired+of+rolling+resistrance.-a0145827934

The other reliable way to get better city MPG
is to rebuild the engine with much higher compression ratios.
With very lean air to fuel ratios (18 to 24)
these high compression ratios won't cause knock like you would normally expect
with tunes designed for maximum horsepower.
A city MPG gain of up to 15% is possible.

If you visit a Ford dealer and look into one of the Escape Hybrids, you will find that the compression ratio there is 11.7 on a 4 cyl engine that can use 87 octane.
Google 'Atkinson Cycle' for more info.

It is even more money
but noticeable city MPG gains
can come from choosing a custom
torque converter.

I can post about 40 more pages of stuff if you are interested.

360 veiw is right about the gear ratios. When I set up my mpg car to have very early low speed shifts I got the best in town mpg. If you have a higher gear you will have less manifold vaccume causing pumping loss, and that is one of the things they always bust there buts to eliminate in production cars and is the main thing behind the MDS fuel savine feture so many newer cars are useing.

I think you are doing pretty good already but if you wanted to make it a little better get the 302 heads, they are a cheap and fairly easy up grade. I would keep the lean burn if it is woking good (as it seems to be). While you have the 302 heads off polish the bridge between the valves so they absorb less heat and that will help keep em from cracking and grind down and the sharp point in the center of the chamber because it causes pre ignition. Those heads will help increase low speed velocity and mixture motion both in the port and in the chamber, those two thing s will help mpg as well as the small bump in the compression.

Id live with what you have and wouldn't change anything. There's a lot of people with these cars who don't even get the mileage you're getting. It also depends on what kind of city driving you're doing. When I drive my car to work and nowhere else i get terrible gas mileage but if I still do city driving but actually drive around more it gets better.

Back in the days, "the Cordoba" got 14 mpg with the AC on.

Steelies on pizza cutter tires.

195/80's floated you around.

And it could bearly squeal one tire.

THANKS for your input guys, a little more info on car, LEAN BURN is long gone from previous owner..choke does kick off to idle after start up..and my city driving consists of a 6 mile trip one way back and forth to work(sometimes thermosat does not open till till 2-3 miles into journey) four times a day city driving with stop lights. I drive sensibly and car does not seem to labor taking off from stop lights(does seem to have a flat spot just off idle which I read may be the step rods may need to be raised) which leads to the starting point I may want to take being t/q has 1/16 smaller primarys and a manifold delivering more torque..again thanks for your input..on a last note I've heard 85 and later trucks equipped with rochester spread bore get better mileage than previous years with t/q.