4 speed vs 5 speed mpg

[Ogrekhan]

Hey all,

Found an 88 festiva for sale near here with 106k on it and almost no rust. Only issue I have with it is its a 4 spd . I've never owned a 4 spd festy. How do they measure up as far as mpg and performance? They want $1,000 for it so I'd have to talk them down some but if it would get close to the same as a 5 spd for mpg I'm thinking of picking it up.

[Roboskittle]

I am pretty sure the 4spd car final drive is very close if not the same as the 5spd festiva so MPG should be very close if not the same to that of a 5spd car. I would get it if its as clean as you say.

[Pu241]

No, the 4spd car final drive is NOT the same as the 5spd festiva.

Drive ratios for gears 1-4 are identical the 5 spds 5th gear is an overdrive, reducing engine rpm by approx 500 rpm vs the same speed in a 4 spd.
Thus MPG increase in a 5 spd can be considerable if driven properly.
Though I would expect that the 4 spd can obtain 40+ MPG, again driving with MPG in mind.
Exact gear ratios are on this site somewhere.
I'll see if I can find them.
Also, certain they are in the Ford and/or Haynes manuals.

[deathegg]

The last time I measured mpg for my 4-speed '88 it was 43 highway, and that was during my cross-country trip last year from CA, with lots of stops to see attractions along the side of the road, and with the car loaded up with my belongings. I think you can easily expect to see 45-50 on the highway - I have gotten as high as 57 mpg highway.

[wybnrml]

Exact gear ratios are on this site somewhere.

Here they are, last post. http://www.fordfestiva.com/forums/sh...ad.php?t=11540

[Pu241]

Thanks, wybnrml!

Thanks to Nonamekid for assembling the chart below:



Note I was wrong in regards to the gear ratio of gears 1-4 in the 4spd vs the 5spd.
In fact they are different!

[TominMO]

Also, you can effectively raise your final drive ratio by switching to taller tires, say on 13" rims. Metro 13" rims are a good cheap upgrade. 155/80x13 is about 4.4% taller than 155/80x12, giving better hwy mileage and tire selection.

[bhazard]

I always thought the festy 4 and 5 speeds had the same ratios too. It looks like the festy andaspire 5 speeds are the ones with the same ratios and different finals. Looks like the 4 speeds run a way high rpm at cruise.

[batstiva]

I don't have a tach in either of my cars, so this is strictly opinion based on what I hear. My 89 (4 speed manual) definitely does run at a higher rpm in 4th gear at 65 MPH than my 90 (5 speed manual) does in 5th gear at 65 MPH.

So bhazard's statement is correct, the 4 speeds run higher rpms than the 5 speeds at highway speeds.

Having said that, the MPGs for both cars are actually pretty close. The 89 pretty consistantly gets 42-43 mpgs. The 90 pretty consistantly gets around 45. My tests aren't as religious as some (no names here, but you know who you are:p) but basically, I make the same drive to and from work everyday, so I figure the conditions are pretty much the same for both cars.

[hot4dl8ly]

I remember getting mid to high 40's mpg with my sisters 88 4spd while taking her to college- keeping the hwy speed reasonably low.

[muscle_Car1]

Umm the real early 4 speeds where that differenet ratio. Mid year 88 they were identical to the 5 speeds minus the overdrive gear.

[Roboskittle]

Ok so like I said the Final Drive ratios are very close. If .08 difference isnt close than I dont know what is.

[getnpsi]

I would not let a 4speed vs.5 slow affect the car purchase if it's that good of shape . An auto yes.

[bhazard]

Difference in MPG between 4 and 5 speeds depends on driving conditions really, lower speeds lower difference, higher speeds more difference. Of course high speeds = more rpm and aero drag anyway...