[godowar]

Guys,

I am looking to lose some RPM's in 6th gear.

Currently I am running about 2400 - 2500 RMP's at 65.
-vs- My Wife's VUE that is running 2100-2200RPMS.

Now I am not looking to race my truck in the quarter mile, nor am I looking to go 140mph, or tow anything larger than a motorcycle or snowmobile trailer.

I am just trying to increase my fuel economy by losing a few RPMS.

Anyone have any idea's?

Different Differentials? Different Transmission? Swapping Transmission gearing?

Anything out there already that I am just NOT finding?

Thanks in advance!

 

[the.phantom]

details on your truck might help?
4x4 ?
5 lugger?
a tacoma is set up for the highway
the 4x4 and pre-runners have lower gears for off road
you could put on bigger tires,

if 4x4 you could put on billies ( shocks) and a aal in the rear and get more wheel clearance for BIGGER tires can give a 2 1/2 lift

here is a tire chart/gear chart so you can play "what if"

http://www.tacomaworld.com/forum/tirecalc.php

i don't know max tire size with out a lift or with a 2 1/2 in lift,sorry,just have a street tacoma

 

[sntckr]

6-speed = 6-lug

Our 6th gear is too short for driving in the 60s and 70s...I feel your pain.

 

[The_Kernel114]

get some 4.10 gears for your truck, but beware you can only get the gears from a dealer and they charge a alot for them. that is probably your cheapest and simplest way to go about lowering your rpm's

 

[Dark Taco]

Just love your truck for what it is. :thumbsup:

 

[nomad]

get some 4.10 gears for your truck, but beware you can only get the gears from a dealer and they charge a alot for them. that is probably your cheapest and simplest way to go about lowering your rpm's

4 Wheel Parts quoted me about $1,500 to install 4.10's.

 

[jpmorrisvb]

How many miles have to be driven to offset this cost? Over the life of your Tacoma will this expense pay for itself?

 

[worthywads]

4.10 is the wrong direction, he has 3.73 so something like 3.31 would be more like it if that's available.

If it's simply to improve mpg it's gonna take a long time to pay for a regearing in gas savings, since you probably won't see more than 2 mpg improvement.

Lift and bigger tires is the wrong direction too, raising the truck hurts aerodynamics and bigger tires are heavier and increase rolling resistance.

 

[godowar]

4.10 is the wrong direction, he has 3.73 so something like 3.31 would be more like it if that's available.

If it's simply to improve mpg it's gonna take a long time to pay for a regearing in gas savings, since you probably won't see more than 2 mpg improvement.

Lift and bigger tires is the wrong direction too, raising the truck hurts aerodynamics and bigger tires are heavier and increase rolling resistance.

Thanks for the info. So shorter gears is what i want ... should i replace them in both differentials?

I would imagine so since i have a 4x4.

I believe there is a sticker on the cab that says what gearing the vehicle shipped with ... anyone know where it is and what the codes mean?

I think they are 4.10's but i am not sure.

 

[trailblzr00]

I would be careful with this. Running at lower RPMs doesn't necessarily translate to better fuel economy. Re-gearing higher may reduce RPMs, but also increases load on the engine/transmission which could actually result in reduced fuel economy. I'm not exactly sure if it would improve or hinder fuel economy, just offering an extra variable you may want to take into consideration (in addition to the cost of having to re-gear both diffs! $$$$$) Not sure if it's gonna have the payoff you're looking for

 

[worthywads]

The payoff does seem unlikely to me, but from a load standpoint it is probably ok, the reason the auto get better mpg is because it has a better OD gear so it appears the motor can handle it.

Better choice would have been the 2.7L from the start! :thumbsup:

Another possible option is regearing the OD. I have no idea what is available from toyota, they may have different ratios. My wife has a Honda Element with a 5-speed and it spins 4000rpm at 80. Some handy modders have taken the 5-speed and added a 6th gear. Honda 5-speed and 6-speed cases are the same so this can be done for under $200 in parts but a lot of work. I've considered it, I have the skills and a friend with the space and tools but haven't done it since the wife doesn't really care.

 

[johnecon2001]

If you have the 6 speed, you have 3.73's stock.

 

[demoncleaner]

I wouldn;t f with the tranny or gearing, gonna cost you more than any savings you'd see in hwy mpg.

I'd work on other driving habits... Driving around, keep her 1300-1800 rpms. Coming up to a light, or stop, stay in tall gear, dont clutch in till about to stop. My rural commute nets me 19.5 mpg all summer. Once on the hwy, you'll obviously be over that, but interstate, I'd just cruise at 70 or less. Hey, no speeding tickets.

I've found Hwy mpg (w/ 6spd)
60 or less = 20 mpg
65= 19 mpg
70=18 mpg
75= 17 if your lucky

 

[trailblzr00]

An alternative for improved fuel economy would be a getting yourself a free-flowing catback exhaust. I averaged just under 20mpg on my 4.0L DC w/5spd auto before my exhaust, and now I get 22mpg! I did a calculation out of curiosity as to how long it would take for my fuel savings to break even on the cost of the system and it came out to over 15 years!! HAHA! It's a good thing my justification for the exhaust was appearance, performance, and sound...not fuel economy...

But if this seems like a viable option for you, you should be able to get a flowmaster/magnaflow muffler and custom piping installed by a local muffler shop for $150-200. My exhaust was a little more expensive (bolt on stainless kits are pricey!), hence the 15+ years break even time :-/

Special note: Since savings are based on current fuel price, break even time will reduce significantly if gas prices jump back up to $5/gallon...comon I'm just tryin to be optimistic here!

 

[dan3209]

Changing the gears to a smaller (numerical) gear ratio might lower your rpm's on the highway, but taking off from a standstill going uphill could become quite a pain, depending on how steep an incline. This could lead to excessive wear on the clutch. Having to chang the clutch earlier than normal, in addition to the cost of installing the gearsets, doesn't sound cost effective vs saving gas (at least at current prices) The cat back idea may warrant investigation. I have done this with one of the early v8 dakotas. Small improvement on mpg and upper rpm performance, but it definitely sounded and looked nicer. Good luck..........................................Dan

 

[Chalkie]

What I don't get out of this whole conversation is why you think you need to compare fuel economy for a truck to fuel economy on a car that has a smaller engine (even if it has the V6)? Seems like an apples to oranges comparison.

 

[worthywads]

^

He's not comparing fuel economy, he's comparing rpm at a given speed.

 

[Chalkie]

I am just trying to increase my fuel economy by losing a few RPMS.

^

He's not comparing fuel economy, he's comparing rpm at a given speed.

Yes, he is. A truck is geared differently than a car for a reason. It is still and apples to oranges IMO.

 

[trailblzr00]

Yes, he is. A truck is geared differently than a car for a reason. It is still and apples to oranges IMO.

If you want apples to apples then compare it to another Tacoma...mine for instance. I'm not running anywhere near 2400rpm at 65mph, its not much more than 2000rpm (5spd auto). So now we're comparing a truck to a truck, which strangely turns out to be the exact same comparison described by the OP.

 

[CupCate18]

Couldn't you simply adjust the idle air control valve? Not much, but some. I know on my old miata it would idle down and die, so we bumped up my idle some. Don't think this would get the RPMs you are looking for though.