4.0L RMP vs MPG

When I'm just cruising my auto shifts around 1500-1600. Obviously if I'm getting on it its not.

 

With my 285/75r16's on my 4.0 I'm at roughly 2200 at 80mph. But I have an AT so I'm not quite sure where your RPM's will fall due to your MT

 

I get 14 MPG at 80-85 MPH, can get just barely over 20 at 55 MPH. Speed/RPM makes an enormous difference in these trucks.

 

This is just a little info on newer trannys.

http://www.autoblog.com/2010/08/18/greenlings-why-do-automatic-transmissions-now-get-better-fuel-e/

 

I think the auto shift points are directly contingent on your acceleration... I can make it shift at 1500, or 2500. That being said I wish I still drove a manual.

 

I use to have a 6 speed off road. It was fun, but I opted for the auto 2nd time around.

 

Why did you switch? What did you like and dislike about both?

 

Accelerating aggressively but shifting at low rpm is best. That doesn't work with an automatic. How aggressive can you accelerate and shift at 1500?

 

I'm not sure if you're mocking me because an automatic can't do that or if you're genuine because you don't have an automatic to see.

So, you shift at 1500, right? And you get to that RPM as quickly as possible?

 

Mpg was the biggest reason. I jumped about 5 mpgs when I went to the auto. I went from 16-17 to 21-22. Highway

I find it more relaxing. My manual was noisy and choppy. The other positive that I noticed is the auto is a bit quicker.

The manual was fun, but I haven't missed it since getting the auto.

 

The best mileage will be at the lowest speed you can go without lugging, at the highest gear. So on an automatic 5 speed, it would be at the lowest speed the 5th gear will engage (around 45mph). The higher your speed, the more the airflow influences the friction of moving through it.
Other factors are much more important. Every time you have to brake, you convert the energy of your movement into heat in the brakes. You have just spent gasoline heating your brakes. SO you want to always glide to a stop, using every bit of energy into movement.
The more weight you carry, the more energy required to get it moving.
The more things you have sticking out in the wind, the more energy required.
The quicker you accelerate, the less efficient the engine is at converting energy into movement.
Accelerate slowly, stop slowly, keep everything lightweight and aerodynamic, use the highest gear you can, keep your engine tuned and clean sparkplugs, use high-pressured thin tires with little tread, keep filters clean from clogs. Drive in a climate that keeps your choke from kicking on. Don't use energy draining equipment(A/C, radio, lights).
Any time you diverge from this, the mpg's go down.
Most people report from 13-22mpg depending on model, mods and driving style.

 

I'm confused. Why would you accelerate aggressively only to shift at a low rpm? Certainly not for fuel efficiency.

 

Maybe the op could find a x runner or 5 lug to swap thirdmemebers with to get a lower gear ratio.

 

Just to clarify, accelerating quicker to 60 is better then slowly building to 60, MPG wise. The optimal acceleration is usually a little faster than what you would normally do... unless you have a lead foot.

Why?

Being in OD at 60, or less, is great for MPG. You want to be there as long as possible. Babying the throttle to slowly reach 60 eats more gas than just getting there and cruising at 60. By slowly accelerating your lowering the time spent cruising at 55-60.

 

I shift at 2000, but accelerate at around 3/4 throttle to 2000 rpm. Light acceleration isn't good for mpg, nor is high rpm acceleration.

 

For fuel efficiency.

 

From fuel.gov
Aggressive driving (speeding, rapid acceleration and braking) wastes gas. It can lower your gas mileage by 33% at highway speeds and by 5% around town. Sensible driving is also safer for you and others, so you may save more than gas money.

From Edmunds
Our tests showed that the most significant way to save gas is: you. And we're talking massive fuel economy gains. Think you need a hybrid? Chances are you've got hybrid-style mileage in your gas pedal foot. Don't mash the gas when you start up. Take the long view of the road and brake easy. This tip alone can save you unbelievable amounts of gas. If you slowed your 0-to-60-mph acceleration time down from your current 10 seconds to a more normal city pace of 15 seconds, you'll feel the savings immediately.

 

I understand the argument for faster acceleration, but consider this:

Slowly accelerating will take longer and quickly accelerating will take less time. However, with that quick acceleration, you cover more ground in the shorter time. So in the same distance, you are accelerating less efficiently even though time is saved.

If there is a flaw there, please point it out. I've tried accelerating faster but I can't seem to nail it. That being said, I do not accelerate as slowly as possible.

 

Are you guys really trying to convince me I'm doing it wrong.

From.

http://www.autospeed.com/cms/article.html?&title=Brake-Specific-Fuel-Consumption&A=112611

anything that allows you to keep the throttle open wider and the revs lower (like changing up to a tall gear and then holding it) will reduce fuel consumption because BSFC will be improved.

We are back to why automatics don't get better mpg than someone that knows how to drive a stick for mpg. Your tacoma with an automatic can't have a wide throttle opening and lower revs at the same time. Mine can.

 

I shift around 5250 when im trying to conserve fuel

but for real I just shift at 2500-3000 cause thats where the shift is the smoothest without me having to really ease off the clutch. I tried driving for MPG for a while...it drove me nuts Ive just accepted the 16-18 mpg in my lifted truck and forgot about it. Tho when you come from a jeep that gets about 150-160 miles to a tank, our trucks seem like hybrids

PS: to actually answer the question, the best method i found for me for mpg was the barely above lug method, but i would shift 1-2-4-6, skipping 3rd and 5th. Regardless of the shift pattern, getting into 6th by ~40mph helps too