Gears on Tacoma too low?

I recently bought a 08 tacoma double cab, it's got the v6 6spd in it. I noticed that the gears all seem to be set really low, when I cruise at 100km/hr, in 6th, the tach is at almost 2500rpm, which seems a little high to me, as I can easily accelerate from 70 to 100 in sixth. Anyways, what I'm getting at is would it be beneficial to my fuel economy to get higher geared diffs, or bigger tires? or would it just be a waste of time. Also I find first gear is pretty much useless when driving on pavement.

 

Best way to get better fuel economy is to get an Auto

 

Interesting,

I have an I4 with a five speed and I would say the gears are too tall. I did a trip to Sacramento (250 mile round trip) a month ago and never used fifth gear once. If the truck had enough power I could probably do 160mph in fifth!

 

I agree that somewhat different gearing would be a good change from Toyota. My Matrix is even worse. One thing that American cars do better than Toyota (the only thing) is keep the rpms low at highway speeds.

But be glad that you have a manual tranny. It gives you so much more control and options for driving for good fuel economy. I'm beating EPA rated mileage by 20% because I can drive smarter than any automatic can do.

 

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Been on all kinds of roads with some long but not overly steep inclines and have never ran into a stretch of what would be considered a highway and not been able to use 5th gear, although if I had to slow down to 30-40 for some reason, a shift to 3rd then 4th, and back up to fifth would hold any speed ~75mph or less. What kind of roads were you traveling on?

 

This.

A 4.0L V6 that I test drove did 70mph at a mile rpm of a little over 2000.

 

I think it has been said before that the 4.0's do 33-34 MPH per thousand RPM's in the highest gear, and that should be the automatic, and may or may not be corrected for speedo error.

My 2.7L 5spd PreRunner does 28 MPH per thousand; 5th gear 0.81, diff 4.10, corrected speedo; was 4.5% fast, so 70 MPH is 2500 RPM, 84 MPH is 3000 RPM, 98 MPH is 3500 RPM, 106.4 MPH (theoretical) @ peak toque @ 3800 RPM, 145.6 (theoretical) @ peak horsepower @5600 RPM

Those theoretical speeds always look so impressive, we need the interstates to be in a giant bubble and under a vacuum...........

 

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How close to 2500 RPM is almost 2500?; You have a 3.73 diff(s) with a .85 OD 6th gear (3.17:1 final drive ratio), Try again on a smooth level road during light traffic because that does not sound correct; 62 MPH @ 2500 RPM's is only 24.8 MPH per thousand RPM, and my 2.7 with 4.10 with a .81 od does 28 per thousand. Your final ratio in highest gear is 3.17, mine is 3.32, and yours WILL travel at a higher speed for a given RPM.

 

How slow were you going???? If I'm not accelerating I'm in 5th gear at 40 MPH.... I also just filled up and averaged 28.339 MPG this tank.

 

I wouldn't change the diffs....as that'll affect ALL gears.

I don't have a manual myself - but seems like Toyota should've geared 6th gear differently.

My gawd... our corvette (manual 6 speed), crusing at 65mph in 6th gear, it's only putting out 1,000rpm. That thing gets better gas mileage than anything we drive!!

Perhaps Toyota had towing & hauling in mind? You need that 'power' for towing & hauling.....??

 

I'll agree the gears are low for some if unladen on the flat, but if your in a hilly area, off-road, often hauling a load or towing they're perfect. Over 65 mph on interstate no doubt the auto's taller 5th will return a mpg or two better. But 65 or less, I can easily 20+ mpg (US gallon), I just got my best tank at 23mpg last week on a trip. Avg 20 summer/17.5 winter otherwise in hilly rural driving, same or better than the auto guys around me. Like marineinexile said, you can easily beat the mpg rating if you drive her right.

btw at 65mph 2350 rpm, 70mph 2500rpm, not sure how your 62mph (100km/h) at 2500 rpm... stock tires?

 

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The corvette has a double OD; with the final being .65 IIRC, and that, along with tremendous torque, and an excellent coefficient of drag allows this. Someone was posting earlier about the 6 speed with the 2.7L, this would work well if Toyota went from the 4.10 down to the old 3.90 ratio, and in addition shifted the 6th OD ratio to around .75-.80, which would give a lower 1st by just a little, and a taller final OD ratio for lower highway RPM's. The 6 speed manual has close ratio's, really too close for a truck. It seems tailor made for the S-Runner vs the trailer tow group who could use a 1st around stock or perhaps something in the 4.4-4.6 range and the 6th as .75-.80; with the stock 3.73, or taller like 3.55; so what if the few times someone tows heavy, they have to use 5th direct.

Janster, I have heard those manual Corvettes are good long range cruising cars due to the mileage. I have a customer that has one, but his only road trip is back to the Corvette assembly plant for one of the shows, he just keeps them in his air conditioned storage building most of the time.

 

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The base tires are 245/75-16, which are virtually the same height as the 265/70-16's and the 265/65-17's. I think mneuls 2500 RPM is from a quick glance.

One thing I did not mention when I compared mneuls MPH/thousand RPM's is that I have 265/70-17's which are off an FJCruiser; which is ~the same height as the 265/75-16 that a large majority upgrade to when leaving truck stock/mostly stock, and that is where my speedo correction comes from.

 

Of course you can always shift into the next higher gear. The point is that the rpm’s are low enough in 4th at 70mph that there is no natural shift point. So the only reason 5th exists is for fuel economy. To be shifting into 5th at 40mph is all about “hypermiling” and I’m never going to do that. I bought the smallest most fuel efficient 4x4 truck so I didn’t have to think about fuel economy.

 

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Shifting into 5th @ 40 MPH at most times is not to the point of hypermilling, unless you see a red light/stop sign just ahead, or are in constant stop and go traffic. The 4th gear @ 70 would only make sense if you were passing someone on a long uphill; you would shift from 4th to 5th @ 70 on your way to 75-80 MPH.

 

When my truck was stock I would drive at 70mph at 2500 rpm. after lifting, switching to larger tires and recalibrating the spedo, I'm at 2200rpm at 70mph. My highway mpg barely changed, and I have pretty heavy mud tires. I think the lower RPMs and increased rolling resistance balanced each other out.

 

Thanks for the quick reply guys, I did look, and at 100 it is actually about 2350 rpm. It seems pretty high to me, I'm thinkin for a six speed, 100k should be around 2000rpm. I prob won't change the diffs but I might just throw a lift and tires on it and call it good. Maybe that is what toyota had in mind when they designed the truck. I think 6th gear should have been just a bit taller though.

 

how far r u from tj? mneuls?

 

this may sound dumb, but what, or where is tj?