[nalbertasr5]

I had a thought today...

The manual for my 2000 5 speed suggests which speed to change gears at. My question is for fuel economy, what are the ideal speeds for the gears? I'm sure people here have more insight than whatever standard thing was printed in the manual years ago. It seems they overstate a bit the suggested speed for each gear.

Where I live there are a lot of 80/km speed limits. Would putting it in 5th gear at 80 have any benefits or would it be harmful?

Can you get away with having it in 4th gear at 65 km/h?

???

What do you other manual T4R guys think?

[jgue467]

Well all else being equal, lower Rs = lower fuel usuage.

Shift points s/b what you feel is needed for the situation, quick or easy acceleration, uphill, towing or just plain cruising, go by the 'feel' of the engine at the time.

I'd say you can upshift at whatever speed (even skip a gear) but should probably keep Rs above 1200-1300 or wherever you feel the engine 'lug' (straining).

Manuals are fun, just don't wind it up too much!

[Tyler James Inc]

Originally Posted by jgue467

Manuals are fun, just don't wind it up too much!

Why do you say this? Have you had a Toyota engine fail from "winding it up too much"?
I typically shift around 2500 RPM, but sometimes wind it up past 4K.
Lower RPMs generally mean better mpg, but not if you're having to put your foot into it.
You have to know the feel of your engine, and drive it accordingly.
You're really not gonna see any noticeable difference in mpg just from shifting at 500RPM different.
I get 16-17 mpg average, and I got 19.8mpg on my last road trip. That included a LOT of high RPM hill climbs at 70mph. After that trip, I think the whole "shifting at lower RPM saves fuel" is a bunch of BS. I was wrapped up to 5k rpm more times on the 19.8mpg tank than all my other tanks/driving combined! Math doesn't lie.

[Scramble]

I like shifting at 3000, 2500 is too low for the 3rz. I'll shift at 4000 getting on the HWY. I like to be moving at a pretty good clip when I change. I hate changing gears & then having to mash the pedal to p/u speed. That feels like a waste of gas.

[NinetySeven]

Hi Everyone! I'm new here, but not new to 4Runners.

I've been driving my 1997 SR5 since 2003, when the original owner (a family member) sold it to me. He's been trying to get it back ever since! 😂

My engine is currently being rebuilt. I've had two cracked cylinder heads on this engine (once in 2007 and another this year). Other than that, my 4Runner has been a faithful friend, and I take really good care of it.

Back to my family member. He believes that I'm driving my SR5 incorrectly by staying in 1st gear too long. I typically shift into 2nd between 2000-3500 RPMs. I've been driving my 4Runner the same way for 21 years and it's never been a problem, but he's convinced that my cracked cylinder heads are a result of this driving style.

Any thoughts on this? I'm open to changing my driving habits if there's any credibility to this theory. Thanks![IMG]

[/IMG]

[phattyduck]

Originally Posted by NinetySeven

Back to my family member. He believes that I'm driving my SR5 incorrectly by staying in 1st gear too long. I typically shift into 2nd between 2000-3500 RPMs. I've been driving my 4Runner the same way for 21 years and it's never been a problem, but he's convinced that my cracked cylinder heads are a result of this driving style.

Any thoughts on this? I'm open to changing my driving habits if there's any credibility to this theory. Thanks!

The '96-'98 had some head gasket issues... So if you missed the signs of that, a cracked head could be possible.

What is his theory on how you should drive?

Generally, I would keep RPMs above 2k RPM if you are accelerating (obviously not possible at the beginning of 1st, but otherwise..). So, shift at the point where the NEXT gear would still be above 2k RPM. The 5vz may be a bit more forgiving than performance engines, so you could drop that a bit for light acceleration/cruising (maybe 1800 RPM?). Working (most) gas engines hard below 2k RPM really hammers on the bearings and is generally a bad idea.

Higher RPM (within reason) for the same rate of acceleration is EASIER on the motor, not harder. The oil pressure is higher, each cylinder ignition event is less violent (more ignition events = less power needed per event), the water pump is going faster (better cooling), less likely to have ping issues, etc.

-Charlie

[NinetySeven]

Originally Posted by phattyduck

The '96-'98 had some head gasket issues... So if you missed the signs of that, a cracked head could be possible.

What is his theory on how you should drive?

-Charlie

Thanks for your feedback!

I've was told in 2007 that my 4Runner might have a higher likelihood of gasket failure. The re-machined engine has run well for the past 17 years, and so I'm hoping the engine rebuild gets me another 17 years of reliable service!

As for how to drive: I think the person in question believes that I should shift no later than 2000 RPM -- 3000 RPM at the highest. I'm open to suggestion, especially since I'll be working with a rebuilt engine and want to take care of it.

[phattyduck]

Originally Posted by NinetySeven

As for how to drive: I think the person in question believes that I should shift no later than 2000 RPM -- 3000 RPM at the highest. I'm open to suggestion, especially since I'll be working with a rebuilt engine and want to take care of it.

That's what I feared - there is a (oddly large) group of people that somehow think that revving and engine is bad. (well, hitting the redline in neutral is bad... but that's not what you are doing)

Here some information from Toyota:


The key thing - look at what happens to the torque curve below 2k RPM. Now look at what happens between ~2500 and ~4000 RPM. An engine is "happiest" in the range where the torque output is highest. This is where cylinder filling is best, engine flow is most efficient, etc. When you need to make power (so, accelerating!), that's where the engine should be. Once you get to cruising, you then you drop to a gear where engine RPM is low...

-Charlie

[NinetySeven]

Originally Posted by phattyduck

That's what I feared - there is a (oddly large) group of people that somehow think that revving and engine is bad. (well, hitting the redline in neutral is bad... but that's not what you are doing)

Thanks so much for this incredible info! Glad to know that I’m not “driving it wrong.” 😎