Hello.
Just bought an 85 toyota pickup 4x4 in Alaska. I plan on taking it on a 2500 mile road trip down to the lower 48 in spring. The snow tires on it are beat.

Can anyone recommend a cheap small tire that will get me good mpg

It ha's 31s on it now but I have been thinking about putting some 195 or 205 size tires on it for my journey

 

Smaller diameter tires will not necessarily gain you MPG. You'll get less forward motion for each revolution of the engine. Basically like running on the highway in 4th when you could be in 5th. Getting larger tires can actually gain you MPG because you'll move farther forward for each revolution of the engine. This works great on flat ground and the highway. But if you're in the mountains or a lot of stop and go it hurts MPG because it does take more throttle to accelerate bigger tires.

The reason many people think bigger tires hurt MPG is because unless you recalibrate the speedometer/odometer it will indicate less miles than you've actually gone. So let's say you put 31's on your truck in place of the factory size 29" tires without regearing or fixing the speedometer. You fill up the tank at it takes 15 gallons. The trip meter says 250 miles. 250 miles / 15 gallons = 16.6 mpg. Not great. but you've actually traveled farther than the trip meter indicates since it's calibrated for stock size tires. So to figure out the real distance you've driven, multiply the trip meter reading by the ratio of new tires to old. So 250 miles * (31" / 29") = 267. So you've actually driven 267 miles. 267 miles / 15 gallons = 17.8 mpg, a good improvement.

Now, with all that said, narrow tires with the same diameter will get better mpg but good luck finding a 195 or 205 width tire in 29" diameter. My suggestion is to run stock size tires or larger. I'm not sure how hilly your trip will be. If it's really mountainous stay closer to stock.

 

Wow.

Was not expecting such an in depth reply.

Thanks for taking time out of your day for that

I'm going to go over the rocky mountains for hundreds of miles.

This 22re is the most gutless 22re I've ever driven. I've owned many 22r's but no re. I think the afm not working correctly. Completely loses all power after about 2500rpm.

I found some 195/60r15 tires at Walmart for $40 each. No name brand but I am going to buy some 33 or 35s when I get back to the united states.

 

That's a pretty drastic change. You'd be going down to a 24.2" tire compared to a stock 29". Percentage wise, that's only about 85% of the stock diameter. Since 4th gear ratio is 1.000 and 5th is 0.850 you're essentiall eliminating 5th gear along with 2 inches of ground clearance. All this costs you about $200 out the door. Might want to just consider replacing it with stock size used tires off Craigslist or something.

 

You need to run the stock 225/75-15s, or alternately 235/75-15 or 30x9.5. The 235s and 30s are the most common of the three sizes, (I've found) and will net you the best average of power and economy. If you're gutless over 2.5k, check timing and condition of plugs/wires. Not a lot of time at 2500 rpm for a spark to ignite fuel/air mix. If it's not enough or late, you'll notice. Also injectors could be developing issues. Any vacuum leaks or TPS type issues?