Carbureted Toyota Pickup Fuel Economy

[SABREMAN]

I have a 1979 toyota pickup 4x4 with a 20R engine. I have a 261C cam from Engine builder and a Weber 32/36 dgv manual choke carb on it. I am getting about 13 mpg, I have 235/75R15 tires on it. I am wondering if this is normal. The plugs look decent as far as fuel mixture, they are light brown. I am wondering what jet size I should use for this setup. I contacted weber and they told me I can buy a jet kit for $80, if I could get by with buying a few main and a few air correction jets I would be happy. Does anybody know what jets I should try?

[Barberdan]

Sounds possible if you have that setup and it is purely city driving without being careful all the time with the throttle but still low in my mind. Only comparison I have is my 84' 22R carbureted 2WD which was stock except for the air cleaner and exhaust and it got around it's rating of 20MPG in the city or more pure city driving. A 4WD would have about 2MPG instantly sucked from it's city mileage. Did you remove any smog equiptment from your pickup or notice anything missing or plugged?

[390FE]

I'm seing 18-20 Mixed driving out of my 87 22R

I've read that the Webbers are good for power and power = "use more gas"

[Barberdan]

I just my first full tank of gas burned in my 22RE 2WD 5-speed single cab since I put in the new timing chain. The timing is advanced a bit and runs on premium and the air cleaner and exhaust are modified to help a bit but the mileage came to 320 miles on almost 12.0 gallons of gas on the nose(the meter ran right on EMPTY but you know it goes MUCH lower and I believe the tank to hold a full 15 gallons). This comes to 26.66MPG! This is with the A/C running almost the entire time and about 2/3 of the mileage at highway speeds but loaded with 300-500LBS when at highway speed with camping equiptment/fire wood. 190,000 miles and its getting significantly better than factory ratings. I can't complain, that's for sure!

[mochester]

i just realized something

since i have 31" tires instead of the factory 28.5, that means my odometer reads low doesn't it?
jeez, i thought i was getting like 15 mpg haha

well compensating for that, i'm getting about 18mpg city, but mine has efi

[Barberdan]

A speedometer error due to drastically larger tires will make your mileage appear very bad I'm sure. Mix that with the extra rolling resistance and air resistance and you can miss the expected mileage incredibly. 18MPG city is great for a 4WD in the city when stock, I'd say you'd doing fine.

[mochester]

well i've been experimenting with using different general shift points through each tank of gas, to see what kind of milage i get. to get 18mpg, i have to take it pretty easy, shift before 3000 rpm, sometimes 2500 in the first 2 gears, and not expect to keep up with traffic up a steep hill. I drove it extra hard and got a hair under 17 mpg...

then again i don't know for sure if i can trust my tach either, a mechanic told me it sounded like 3000 rpm when the tach said 3500

my meters are all out of whack

oh well

[mudseeker]

when i had a five speed i shifted by ear, never payed attention to the shift light on the dash

[Barberdan]

Really it's a combination of thorttle position and RPM that determins the rate at which fuel is pumped through the engine. Try to keep the throttle position light but don't be affraid to go 15MPH in 1st, 25mph or so in 2nd. I find shifting earlier than this esspecially in the first two gears puts the engine is a range where it makes extremely little power(1200RPMS or less about, right above that there is suddenly MUCH more power) and feels unpleasant, like it's in lugging territory. I keep the rev probably between 1800 and 2800 to my ear knowing that the rev limiter kicks in at 6300. I put the pickup in 5th gear about the time I hit 40MPH, no earlier. I ought to put a tachometer on this thing.

[chevyguy]

Dont lug the engine by shifting too early, Motors dont like that and these little motors wont handle it for too long. i just shift by ear and feel.