RPM guide? 03 taco 3.4 AT

Just what it says...

looking to compare some RPM's with you guys & see if its where its supposed to be.


AT 4wd
3.4 v6
tire size= 265/70/r16

didnt see a chart/graph in the stickies or search function.

whats your average RPM (mine listed below)

55mph =1750

65mph = 2100

75mph = 2400

 

I mean.. does it matter? As long as I don't have a high idle I don't pay much attention to the rpms. It would be impossible to remove all the variables, especially as you're not even sure what size tires you're sitting on, let alone weight of the trucks and accessories, driver, how much gas is in the tank.

 

its not life ending.... & not trying to be pinpoint on it.

just trying to get an idea where people are in these on daily use.

whats running it too hard for this particular motor/ vs whats the normal ranges people run them at?

like 2800rpm at 75mph= is that pushing this little motor? OR is that just what it runs & its no big deal.

seems like i spend a lot of time above the 2000rpm mark unless im just puttering around town.

 

RPM is a function of gearing, tire size and vehicle speed, unless the torque converter is unlocked. It kind of is what it is, not really sure what you’re getting after?

 

will post mine up after road checking again tomorrow. then we'll see what you guys say. its a bone stock 3.4L w/AT.

this isnt that odd of a question, am i the only person who actually looks at the gauges?

the long & the short of it is: am i running it too hard? or is this where they range?

 

It’s all in the link below.
Fill in your information. If it doesn’t match, you either entered something wrong, or your truck has different “parts”.
Click the drop down menu, the transmission and transfer case are there. Click the one you have in your truck.

http://www.grimmjeeper.com/gears.html

 

What do you mean by running it too hard? Engine speed is directly related to how fast you’re going and what gear you’re in, there isn’t really anything else to it.


I’ve driven more MT vehicles that didn’t have tachometers than those that have them. They’re not that important for your average street driven vehicle.

 

thought this was a pretty legit question, so must just be me.........

whether its my tractors, backhoe, mini truck or vehicles, i always try to find where these things run the best vs diminishing return & excess wear. more rpms isnt always the answer. sometimes a vehicle is set up for best performance in a certain range.

2800rpm @75mph on the highway seemed like a lot. but ive got no experience with these motors to actually know where the real sweet spot in them is.

wifes Jeep is only turning 1850@ 75mph
Daughters Jeep is turning 2200 @75mph
my other truck only turning 2000 @80mph

seems you guys dont care what you run em at. fair enough.

 

I see what you’re getting at. At long as you’re not flogging it along at redline, they don’t really care. My taco is geared really low, which is great for crawling, but also means it runs at 3000+ keeping up with freeway traffic. 237,000 miles now - doesn’t burn oil, runs like new.

Generally though, larger engines with more torque can be geared taller and will turn slower to make the same vehicle speed. Smaller engines don’t typically make as much torque and so need to be geared down, resulting in higher engine speeds.

Tractors and backhoes are a different animal though, and finding a sweet spot for those makes much more sense to me.

 

I'll bite, when I'm on the interstate with cruise control on, running about 72-73mph the tach is just about 2250 rpms. i get decent gas milage when running this speed, about 22.4-23 mpg. I really can't complain and the 3.4 L isn't working to hard to maintain that speed and rpm. Stock 2003 DC AT 4x4 TRD.

 

thank you to all.

now we've got some input. (also got some by PM) even more impressive is that 22pmg at highway speed with the cruise set!

felt the 3.4L was working pretty hard to maintain that speed & didnt want to push it too hard at 232K. it purrs like a little kitten & want to keep it that way. the red lines on a tach are always ridiculous in how hard to actually run something.

 

What size tires?

I’m in an 04 DC 3.4 and have similar rpm’s at that speed range.

But I get 19-20 at best.

Tires: 265/75r16. This size tire is true for the speedo/odo. Anything smaller and you’re getting higher speedo/odo numbers and thus higher mpg numbers.

My 98 has 31” tires on it which is undersized for speedo/odo. It’s not linear but it’s about 2-3% off. Which explains why I’m calculating 22 mpg using the odo / gallons pumped.

 

went back and added my tire size in to the OP. havent made it to town to get the rpm numbers yet.

265/70/r16 discovery RTX's is whats on mine.

 

Those are slightly undersized. Your Speedo and odo are running higher than actual speed and miles.

This of course is independent of rpm’s. But if you’re calculating mpgs you have to account for the correction.

 

then i dont have to worry about getting a ticket at 75-78mph.

fuel mileage for me is not real important in this little critter. if it gets 20ish? thats just awesome.

man i gotta get out of the house. its raining, cold, windy & wife has the day off, need to get moving for the day.

 

265/70/16 Hankook Dynapro (old version) My milage is according to my Scan Gauge, and I've checked it when I fill up. Just driving around town running errands, I get about 17-18 if I can keep my foot light on the gas pedal. I haven't gone on a road trip in years, but I'd love to just to see if I could get that milage for a complete tank of gas.

 

ok finally got out on a perfectly flat road couple miles long with the cruise set at each speed & made multiple passes.
now for those who want to get super picky? sunny, mid 50's, no wind & its probably not perfect... but its close enough for what i was asking.

heres what i got:

55mph =1800

65mph = 2100

75mph = 2400

all in all it was better than i thought. thanks for playing along.