I got the idea from Bigdavewilson to post the RPMs for various speeds.

'06 F-150 145" wheel base (Reg Cab, 8' bed)
5.4L auto (heavy duty pkg) 4.10 limited slip diff

50MPH - ~1600 RPMs
55MPH - ~1750 RPMs
65MPH - ~2100 RPMs
75MPH - ~2300 RPMs
80MPH - ~2500 RPMs

The RPMs are abouts while driving and looking at the gauges in traffic. The figures might be off a little bit, but close enough to get an idea.

What's your truck's motor turning at various speeds?

ChadStar

 

Sounds right to me, I have 3:73 and at 75 I hit about 2100rpm and about 1850 at 60.

 

Hi Chad,

Had a little time on my hands and was just checking to see what happened to you. Thanks for the info on the engine rpms with the 4.10 gears. Most of us are running the 3.55's or 3.73's and there's lots of info with them. Not much with the 4.10's though.

You'll notice that I'm not a lot of help when it comes to mph and mpg questions because here in Canada our trucks are set up for kilometres per hour and even when we old timers convert to mpg we use the Imperial gallon which is 40 fluid ounces, not 32 like yours.

We don't often think of such things, but the engine rpm at a given speed is also somewhat controlled by the automatic transmission. One of the first things I noticed after I got my tuner was that the rpms cruising down the highway were somewhat higher which is a factor of the reset transmission specs (ie. much more positive and quicker shifts).

Any decision yet on new tires? You've probably found out by now that nobody wants the Generals as take-offs for the same reason that you don't want them on your truck. It's just a sad part of the game with many OEM tires.

BTW it's kind of a thing with some of us to post pictures of our trucks with a little mud on the tires (I love that song). Get yours dirty yet?

Dave

 

At 70 MPH 1750 rpm. That's with a 5.5 L Volant cold air intake system,3.73 rear;KR supercrew with a cap on shortbed.

 

Hey Bigdavewilson,

Good to hear back from you. I've been dealing with ahead cold so things were put on the back burner for a bit. Up North you have the mettric system so I can see how that changes things. Overall, I was pretty happy with the way the truck spins at different speeds. Good to hear some feedback, and thought that info would be helpful.

The tires are bumming me out, not a lot of choices out there. The Generals are dissapointing. I believe they are not tru and can feel it different speeds. Not a vibration, but they seem to, for a lack of a better description, kinda flop around depending on road condition. Hard to explain, but I have been felt this before in other tires. I am going to drive them through the winter and will probably put the Michis on next year. Hoping the LTX M/S are made in my size.

I have gotten the truck dirty. Hauled a load of wood with it last Sat. Did take some pics, but not with a digital camera. I will update my album in the near future.

Thanks and talk soon,

ChadStar

 

2005 F150
4.2 V6
3.55 rear end

Best I can In OD w/ torque converter locked, it is turning about 31 rpm / MPH. I'll try to remember to double check it.
If my memory is correct:
60 mph ~ 1800 rpm
70 mph ~ 2100 rpm
80 mph ~ 2400 rpm

180 mph ~ 5600 rpm (redline)


I know, I know. It won't do 180 mph.