My Maverick with the 200, used to get somewhere around 19-20mpg, driven pretty hard, city and hwy. Then, I had a 250 in it for the last 10years, and towards the end, with it so wore out it used 1qt of oil per 75 or so miles, only seemed to get 15-16. Now, the new motor, a rebuilt 1978 250, seems to get about the same. Even though power is much better, driven easy, gas mileage sucks. It's a 71 Mav, 250, RBS carb, C-4, 2.79 gears, no power steering or A/C, mostly stock stuff. What does everyone else get? If this is all I get, I might go to a 302...Was not a problem till I started driving it 60 miles a day!
What can a 250 get for gas mileage?
- Thread starter Duane
- Start date
6bangerwanab
Well-known member
to me it all sounds backwards. rebuilding should allow it to get better. but engines also get a bit more after they wear a little. and hwy driving should up the average, esp with such tall gears
is your speedo correct? you could be doing better/worse than you think.
how good is the tune? a good moter might need another tune.
what kinda performance mods did you do?
is your speedo correct? you could be doing better/worse than you think.
how good is the tune? a good moter might need another tune.
what kinda performance mods did you do?
A
Anonymous
Guest
I'm hoping that the theory about fresh engines not getting good mileage is correct and that mine will get better- it's not good at all right now!
A
Anonymous
Guest
I've just returned from a 1,600 mile trip from Sydney to Melbourne and back.
Mostly country miles sitting on 55 to 60 mph and averaged consistent 22 MPG. This is in a standard 2V with 200,000 miles on the clock.
When I drive around town it drops to 17 MPG.
As my memory serves me however an imperial Gallon is slightly more than a US Gallon. (Imperial Gallon is 4.5 litres).
Mostly country miles sitting on 55 to 60 mph and averaged consistent 22 MPG. This is in a standard 2V with 200,000 miles on the clock.
When I drive around town it drops to 17 MPG.
As my memory serves me however an imperial Gallon is slightly more than a US Gallon. (Imperial Gallon is 4.5 litres).
Howdy All:
My "Built" 250 with an Autolite 1.08 on a modified log head, an SROD OD and a 3.50:1 rear gear in my '65 Ranchero gets 22 - 25 on the highway depending on speed, and 15 - 17 around town.
Compression is up, heat is down- speed and fun go up- MPG goes down. Oh, but the thrill!
Adios, David
My "Built" 250 with an Autolite 1.08 on a modified log head, an SROD OD and a 3.50:1 rear gear in my '65 Ranchero gets 22 - 25 on the highway depending on speed, and 15 - 17 around town.
Compression is up, heat is down- speed and fun go up- MPG goes down. Oh, but the thrill!
Adios, David
I got mid to high twenties with my 250. That was with an AOD and 3.55 gears, but I attribute it mostly to the zero deck, high compression, good quench, and electronic ignition.
A
Anonymous
Guest
Hello all --
I get pretty close to MustangSix...
My 65 Mustang coupe with a basically stock 250 [mid-70's block, 1980 head], draw through turbo @ 4# boost, T5 manual transmission, 3.2 diff, electronic ignition, and 195 70 x 14 wheels, on 92-93 octane gas, can often hit 27 mpg on easy freeway driving, usually runs in the low to mid 20's for mixed highway/city driving, and gets under 17 mpg when I'm having lots of fun with the turbo.
--- Barrett
I get pretty close to MustangSix...
My 65 Mustang coupe with a basically stock 250 [mid-70's block, 1980 head], draw through turbo @ 4# boost, T5 manual transmission, 3.2 diff, electronic ignition, and 195 70 x 14 wheels, on 92-93 octane gas, can often hit 27 mpg on easy freeway driving, usually runs in the low to mid 20's for mixed highway/city driving, and gets under 17 mpg when I'm having lots of fun with the turbo.
--- Barrett
and I did a lot of HOT RODDING.....check my sig 
A
Anonymous
Guest
My well worn 170 with the c-4 and 3.0 rear was getting about 16-17 around town and 19.5 on the freeway at 60mph . My "new" 200, suppossedly rebuilt about 1,800 miles ago, is going about 160-170 miles on about 12 gallons. Granted I'm still dealing with carb and distributor issues, but this is much worse than I expected. Somebody please tell me it will get better!
Sedanman
Sedanman
Howdy All:
For max mileage make sure to;
*Maintain a good tune up.
*Max initial advance with no ping.
*no drips or leaks of any kind.
*lowest idle and choke setting possible. Avoid idleing and cold starts.
A cold engine will warm up more efficiently under load than idling, so start up and drive off slowly. A piece of custom fit cardboard in front of the radiator is SOP come winter in the Northern climes.
*least accelerator pump possible.
*Tune for highest vacuum.
*maintain as much engine temperature as possible. Did you ever notice that you get better mileage in the summer than the winter?
*Max air pressure in tires.
*less weight.
*Slow down on the highway. Avoid stop-and-go traffic in town. Basically, don't have any fun at all. Absolutely no stop light drag starts. Drive as if you had a raw egg between you foot and the gas pedal. Anticipate a stop and coast whenever possible.
Measure consistantly and accurately. If you don't you're just guessing.
Adios, David
For max mileage make sure to;
*Maintain a good tune up.
*Max initial advance with no ping.
*no drips or leaks of any kind.
*lowest idle and choke setting possible. Avoid idleing and cold starts.
A cold engine will warm up more efficiently under load than idling, so start up and drive off slowly. A piece of custom fit cardboard in front of the radiator is SOP come winter in the Northern climes.
*least accelerator pump possible.
*Tune for highest vacuum.
*maintain as much engine temperature as possible. Did you ever notice that you get better mileage in the summer than the winter?
*Max air pressure in tires.
*less weight.
*Slow down on the highway. Avoid stop-and-go traffic in town. Basically, don't have any fun at all. Absolutely no stop light drag starts. Drive as if you had a raw egg between you foot and the gas pedal. Anticipate a stop and coast whenever possible.
Measure consistantly and accurately. If you don't you're just guessing.
Adios, David
A
Anonymous
Guest
Hi David,
For best MPG, should intitial advance (without vacuum) be set for the most advance without pinging, and then the vacuum set for as much advance as possilble with a good idle quality, or the other way around? There's been much discussion of this in another thread, and I understand that I want about 15 deg. vac. advance at idle. I'm just not sure wich would be better - 12-14 deg. initial (this worked on my old 170 with no pinging- not sure what vac. was set at, though) with 10 deg. of vac. advance, or 10 deg. of initial with about 10-15 of vacuum.
I'm currently at about 10 initial/10 vacuum for for a total of 20 with the line hooked up on my 200. 15 vacuum with 10 intitial get's poor idle. Should I back off the vacuum and increase intitial? I don't think I can get any more shims in the vac. cannister
Thor
For best MPG, should intitial advance (without vacuum) be set for the most advance without pinging, and then the vacuum set for as much advance as possilble with a good idle quality, or the other way around? There's been much discussion of this in another thread, and I understand that I want about 15 deg. vac. advance at idle. I'm just not sure wich would be better - 12-14 deg. initial (this worked on my old 170 with no pinging- not sure what vac. was set at, though) with 10 deg. of vac. advance, or 10 deg. of initial with about 10-15 of vacuum.
I'm currently at about 10 initial/10 vacuum for for a total of 20 with the line hooked up on my 200. 15 vacuum with 10 intitial get's poor idle. Should I back off the vacuum and increase intitial? I don't think I can get any more shims in the vac. cannister
Thor
I think I need to lean the carb out, but I don't know anything about how to get smaller jets for it. I have my dist set for 38 degrees total, no vac advance hooked up. It all comes in pretty quick, no ping, but any more, and I think it will. If I were to hook up my vac, then would I still be looking for 38 total with the hose hooked up? Or does it maybe go higher at cruise (in the 40's), and when you tip in (or floor) the throttle, it loses vacuum, and loses advance, and won't ping? I hope I asked that right, it's how I did my 460 when it had a factory dist in it. But I ran it at 40 degrees, all mech, no vac, and in by 1600rpm. Makes for great 60ft's at the track. What carb is best for mileage? The Mustang in my avatar is my toy, but this thing needs to get better mileage, so performance can go down some.
