Here is what I have:
1998 Ranger 2wd
2.5 I-4
30x9.50 tires
3" body lift
8.8" rear end 4.10 gears (stock)
Manual Transmission
Exhaust = No Cat w/ a glass pack

Here are my problems:
Gas mileage in town 22mpg at best
On the highway it goes down to between 13mpg and 16mpg
When I have the truck in 5th gear I have to basically keep the truck floored to maintain my speed. If the road is anything other than flat I have to downshift to 4th to keep from bleeding of too much speed, and I still do. I can live with the gas mileage stuff if I had some HP, but I don’t. If I have any weight in the back or god help me I try and pull my trailer with one 4 wheeler in it I can forget 5th gear and almost forget 4th.

So I guess this is my (long) question:

1. Do I change my rear gear ratio to like a 4.50ish and add a K&N intake system, Tornado and throttle body spacer? (Is the stock intake manifold as bad as I hear, and change it too)?

2. Find a 3.0 or 4.0 V6 and just install that? Will the Mazda tranny have to be changed also?

3. Just go all out and stuff a 302 down in the Ranger?

If you guys have better ideas than these please feel free to help me out. I just want some giddy-up and go out of my truck. If all I'm going to get is 18mpg out of my 2.5 I might as well have the HP that goes with that kind of mpg. I just don't know what to do? Thanks for the help guys.

 

after i put on the big tires the hp and mpg went down in my 3.slow. i haven't done anything performance wise to it yet but plan on it. i'm not sure what gear i have in it but it will be the first to go. i don't have a stick so i'm forced to stay out of od most of the time. its been this way for a long while and just dealt with it but now thats its paid off, i'm gonna start tinkering.

 

You have an 8.8" Nrear on a 4 cylinder Ranger? Why do I doubt that if it wasn't a swap-in?


1. Wrong approach. Gears may help, going from (I assume) the big 14" tires to what you have is a ~10% increase, so if you didn't not get a stealership to program the speedometer to account for the difference, you're readings are off. You are travelling 15% fewer miles and thinking you are using the same amount of fuel as before. Only the cylinder head ports on these 8 plug engines suck. You are thinking too hard about everything else. Port/polish the head ports and you're fine. No TB spacer, no K&N, no tornado, nada! It's that simple. I would go to 4.55s if you are real concerned and your speedometer is correct. When I get the spare 2.3L for my truck worked on, it gets a head porting and a cam. That's all I want and feel the need for.

2. Not really necessary if you do as above. The 3.slow is NOT an option IF you wanted to swap. Why only go up one size for v10-like gas mileage (Okay, 2wd manual tranny v10 F250 reg cab mileage...) and 4 cylinder-esque "power"?

3. In a 98-01 Ranger, it's the best swap call. Search the engine swap forum. The links to get you going are in there.

***Floor in 4th, not 5th. Overdrive (5th) is for cruising, not passing. That will kill mileage, whther or not your speedo unit is off.

From what you say, your speedo is waaaay off at higher speeds. The difference is minimal at low speeds, maybe a handful of miles off, but 10-15% or so grows once you get up to 70.

 

Just to clarify something, the difference will not vary based on the speed, the final drive ratio is set but wrong for the calibration.

 

Not to mention 4.10 is a horrible highway ratio, that could account for your bad gas mileage. At least your acceleration won't suck.