RPMs at Highway Speeds

I have a 2002 Tacoma Double Cab 3.4l V6 4-Speed Auto. I live in the desert and sometimes the flow of traffic on the freeway is 90+ MPH. When I get to about 80 MPH the RPMs are at about 3,000. I was nervous about going any faster for long periods and damaging the engine.
Is it safe to drive faster than that for long distances?

 

I don't think engine damage is your biggest worry when you're talking about long periods of time at 80+ in a 22 year old pickup.

As for the engine, as long as it is in decent condition, running at 3000 RPMs isn't gonna hurt anything, but your gas mileage is gonna tank.

I'm really curious where freeway flow is over 90.

 

I would think you’ll be OK. Maybe put a separate transmission cooler on it for shits and giggles

 

I live in Nevada, sometimes on I-80 the speed limit is 80 MPH, so the flow of traffic is even faster.

 

I’m 0-60 10 minutes, now. The only way I’m doing 80 is if I drive off a very tall cliff.

 

The engine will love running at 3K RPM for any length of time you give it. Right around 3K is where it's at the peak of it's power curve, and so as happy as can be, albeit at less-than-ideal fuel consumption.

Ideal fuel consumption happens between 2250 and 2500 RPM.

I'm running 4.88 gearing and 255.85/R16 tires (~33") and so when I'm at 62mph, I'm right around 2750 RPM. I will drive for 20+ hours that way (with short breaks for fuel, food) to start a lot of my trips, as I head south from WA to the Mojave. Or SE Utah. Or wherever.

 

As @turbodb mentioned. A 5VZFE should live pretty much between 2200 and 3200 on the freeway.
Although I'm not sure how you're getting 3000 RPM at 80
Stock tires @ ~ 31 inch diameter with 4.10 gears at 80 MPH is about 2500 with Overdrive on and about 3750 with OD off
* If you're not running at least "31" inch tires (265/70R16) I suggest you do that. They should fit.



FWIW I drove around with 5.29 gears and 33s for about a year (I knew I was going to go 35s)
80 MPH + 5.29 + 33 = 3000 RPM. I had no real issues with it at all. Just paid for it at the pump. (I don't typically drive the truck that fast anyway)

Then I did about a year with 5.29 gears and 35s for about a year
80 MPH + 5.29 + 35 = 2850 RPM. Again, no real issues.


NOW... I'm at 5.29 gears and 37s
80 MPH + 5.29 + 37 = 2700 RPMs... In case anyone is wondering. 37 + 5.29 is the sweet spot. I just did a 12 hour round trip to King of the Hammers and was hovering at around 75-80 the entire way. (I noticed I drive faster now lol)



All above RPMs are slightly lower because actual tire size is always smaller than advertised. All above RPMs are assuming the overdrive is on. The above numbers are also rounded and estimates because its a generic calculator that doesn't necessarily use exact Toyota final drive numbers.

 

And one (final?) thing to add to this entire discussion - AT vs. MT

Everything else being equal, at the highest gear (5th on MT, 3+OD on AT), you're going to see a MT running about 500 RPM higher than an AT at the same speed. For example, if you feel comfortable running for an extended time at 2500 RPM on your tach, someone with a MT is going to be seeing 3000 RPM if they are running at the same speed. So, you know the engine is going to be just fine if you hit that same 3000 RPM, because it's "normal" for the MT guy (like me).

Edit: 3+OD in the AT, not 4_OD. Weird, I think I knew that, but forgot.

 

Except it's 3+OD on the AT
4th is overdrive

Here's an example





They call an A340 a 4 speed trans. The only way it's 4 speed is if you include the overdrive. It's actually a 3 speed with an overdrive. A long time ago a bunch of people wanted to argue about that with me. It's probably Po-tay-toe vs Po-tah-toe... but there is a difference.

There is no 4+OD because number 4 IS overdrive.

 

there must be some oddity with that 2200 RPM range and the 5VZFE (with or without R150F transmission)

my old '97 rig is now suffering its 3RD ailment at that particular RPM point that ONLY pops (or popped) up there and went away at slightly higher RPMs in all gears above 1st

355k
5VZFE
R150F - rebuilt by YOTA1 from an '02 R150F after the 2nd ailment encountered was finally discovered