1990mudslut

hey all,I have a 1990 Toyota pickup with the v6 3.0 auto transmission and 4:10 gears.I have been running 31x10.5s for a while and made the bump today to 33x12.5s.I used to cruise around in o/d at around 2800-3000 rpm now its down to 2000-2500 rpm in o/d.My question is would it be more fuel efficiently to role in 4th gear with o/d off?


thanks

Kiroshu

well ur rpms wne t down alittle due to the fact the truck has to pull alittle harder on thoose bigger tires. o/d is require for highway driving in automatics and is basically there for gasmileage reasons and so you can go higher speeds without running too high rpms and burning out ur tranny. just keeping driving it. its fine.

1990mudslut

well I mean I know all that but from what ive been reading the 3.0 gets best gas mileage around 3k rpms.so If i was to run in 4th with od off then i would be running around 3k rpms and technically should be getting be better gas mileage correct?

Tubbyfatty

Just regear to 4.88s, wait, you have an auto so 5.29s would be best.

Kiroshu

i know alot about the 3.0 but i've never heard that. Maybe its true but i've never heard 3k rpms for good gasmileage. If your cruising down the highway at 70mph the rpms are going to be close to 3k and being on the highway naturally will get good gasmileage on the highway. i've never heard that an i would not worry about it. My dads got a 3.0 and i've had 2 3.0's before and hes 3.0 gets about 200miles to the tank city driving. Dunno about highway its prolly about close to 300 highway. but his truck has 33 12.50s on a 3 inch bod lift and it shifts the same and has about the same gasmileage with the stock tires it had. Generally low rpms better gasmileage. Generally. just drive it its fine why are you getting terrible gasmileage or somethin?

Kiroshu

you could do a gear swap like this guy is suggesting and it would help with those bigger tires, but i deal with OEM so yea thats up to you...

Tubbyfatty

When you regear, you will gain your mpg back in town and on the hwy. you will also get your power back.

And your speedo is off a few mph's with bigger tires and stock gears.

Junkers88

I've always been told that if you can run your rig in or near the power band then you'll maximize the mpg (with normal driving) and have less wear on the running gear since the engine won't be struggling to stay at speed or over running (red line). I would say run it in 4th, o/d off, for a tank of fuel and see what it does.

The best bet is to regear but that can be either a pain (trying to find thirds in 5.29) or expensive (having your existing thirds set up with new gears). Sometimes it is both.......

1990mudslut

I just got the tires today and the truck is not sluggish feeling by any means at all to me.I will be driving it down to panama city Saturday and was just wondering what would be the best way to drive it.It will be receiving a 5speed transmission once I come back

I just went out and drove it again on the highway my speedo is 15mph exactly off the rpms in 5th gear is 1500 lol it will cruise along fine at that but on hills or slopes it drops to forth.

dutchboy

200 miles to a tank...in the city?
300 on the highway?
Lifted on bigger tires? I truley find your mileage per tank not to be true.
Dude...
I have a 3.0, 90 4runner,auto w/od...on stock tires,no engine or rig mods,at all and I only get a little over 200 miles per tank...on the highway!!!
I seriously doubt,that a 3.0 with bigger and wider tires gets better gas milage than a stock rig...or everyone would be slamming bigger tires on their rigs.

1990mudslut

h/o now dutchboy on my 31x10.5 bfg a/ts on 4:10 gears auto 3.0 I used to get right at 240 with a 50/50 mix of city and highway and keep in mind that my speedo was 8mph off so really and truly I would get more than 240 miles per tank.

also his trucks could have the 4.88 gears that came stock for 31s

dutchboy

"also his trucks could have the 4.88 gears that came stock for 31s"

Well, you are right. I didn't consider his gearing. Then again...he didn't mention what his gearing was.
But do you really think that with 4.88's he could get 300,with WIDER tires?
Like I said earlier,if his claim were right...why wouldn't we all be jamming oversize tires and gear swapping?
Everyone chimes in on this site,trying to get better fuel milage,and all of a sudden...here's a guy with oversize tires and "possibly" different gearing dusting us ull in milage?

I have the same set up as you and on highway alone...cruise control on,(I always have o/d engaged). I get roughly 230 per tank.
I'm thinking if I upgrade my O2 sensor (still fac. original), I'd pry do much better.

KVRunner

I am running 33X10.5 tires on 4.30 gears and I am getting a little over 200 miles in town. Stoplight every quarter of a mile. But then again I have a 5spd.

Kiroshu

it might help to say that the motor in his truck is new and yes it gets about 200 miles to the tank no lie i don't know how but it does. maybe not quite 300 highway but close. I've had lots of 3.0's and they too average about 200 miels to the tank. I had a 5-speed 88 3.0 that got exactly 260 miles to the tank city driving.

Dan.3

this makes absolutely no sense. Its either you are in o/d or out of o/d

dutchboy

"i know alot about the 3.0"<<<
"yes it gets about 200 miles to the tank no lie i don't know how but it does"<<<

???? If you know alot about the 3.0's...how do you NOT know"?
I'd still like to know how you're even coming close to 300 on the highway...with taller and wider wheels!?
What rear gears?

260? City driving? Are you really serious? All that stop and go and 260 to a tank in the city? C'mon...
I sincerely don't mean to discredit you and what you are saying,but that just seems so...unreal.
Please forgive me,but that's just nuts to be able to do that good...on big tires,and yet no one else with big tires comes close to that kind of milage...let alone with stock size tires.
Again...what's the gear ratio in the rear?

So a manual gets better milage over an auto...in the city?
I'm just having a real hard time figuring this one out.
I'm averaging 190-200 city,230 highway on 31 x 9.5"s and I baby it. I never got my foot into heavily,I run with almost zero extra weight...I even keep her washed frequently to help with aerodynamics!!!

Kiroshu

Ok i know your trippin and i really don't want to take over this guys thread but um vehicles are different. And so are the people who drive them. My dads 1990 3.0 3vze 4runner SR5 new motor 50k ago with 33 12.50's and a 2 inch bod lift does get about 200 miles city. Highways a lil more close to 300. If tuned right they will get good gas mileage. It does not have any gears its totaly stock except for the tires and lift and a K&N cold air intake. Yours may be deprived of something. Idle too high, dirty air filter, dirtly fuel filter, o2 sensor fouled, vac leaks. Its called fine tuning and care. TLC. I have had 2 3vze trucks myself. I had an auto 3.0 1995 model and it got about 200-210 gasmileage city, dunno bout highway. It was ran totally stock with 31's I also had a 1988 4runner SR5 3.0 3vze 5-speed. This truck was the best gas mileage truck i ever had i almost could not believe it my self man, as much as i could not believe it this truck got about 256-260 miles to the tank city driving. Fine tuned kept clean will take your truck all the way. For some reason most of the 3.0s i've had acctaully are not much differant if not better than 22r's. At least the ones i've had. It my be my trucks it may be ur i dunno. All i know is i'm not lying.

Dan.3

i averaged about 20 to 21 mpg doing 65 drafting a tundra that was pulling a 55 on a trailer. and have an 88 v6 auto with 4.10s and 35x12.5.15 trxus mts and some body armour to help with wind resistance










btw my v6 has 3.4 liters

dutchboy

Well,I agree...I didn't mean to take over the thread with this issue,but...(final post). Respectfully,without others agreeing with what you state. Im convinced not to believe this 100%.I fully understand,"fine tuned". I do have automotive schooling and all my buds are gear head/pro drag car builders. I get it...believe me I do.
Stock gears!?
Their is just NO WAY...with larger tires,lifted,even fine tuned and the best driving skills,is not gonna get 300,per tank on any highway.
Once again...if that was the case...we'd all be doing it.
Brand new, a stock 3.0, in this specific rig,like mine...only averages 15-17mpg. Even when Yota 4runners came out in 90...they only got 15-17mpg. I never said that you were lying...but that's a whopper! I only say that because no one...no one on here(that I have seen) is getting the milage you are claiming.My rig isn't deprived of anything. No vac leaks...at all! Always clean air filter,always good plugs,wires,etc. I do need to change my O2 sensor,but again,...no one else on here gets the milage like you claim.
You must be driving downhill everywhere you go,with a much larger gas tank.

dutchboy

AMF CT2004...
Did you get 300 milers per tank on the highway?