I drive a ford motor (4.6L) but have also driven a few 5.4L's as well over the years. I have driven 4 or 5 different people's GM's or Chevy's too.

Why do GM motors rev more per throttle than Ford motors. Meaning, i can give a moderate amount of gas to my truck and other trucks alike and the rpms go to 2k and stay around there or less as the truck moves through the gears. My mother-in-law's Tahoe with the same amount of gas moves through more of an rpm range. Why is that so?

I just feel as though i really have to step on the gas in a ford to get around 3k rpms but a GM motor gets to 3k rpms with much less throttle.

Has anyone ever noticed this difference?

Its almost like the ford motors lug around a lower rpm and the GM motor likes to rev to achieve the pick up and go it needs.

IDK about the 4.6l but the 5.4l has better low end torque than the 5.3l. At least better than the old generation 5.3l. Tows better, too.

Is your 4.6 in a f150

Its because the Fords use a diffrent fuel parameter setting while driving at lower rpm. The 5.4 doesn't always use gas injected out of the injector when you push it to the floor at a low rpm. It uses air & vapor. Plus the way the plugs are desighned on the motor if it had fast rpm rev up it would blow the spark plug out of the head. The spark plug blowing out does and has happen. Kind hard to explain with out writing a service book. But 5.4 is a good modular motor that seems to get around 225, 000 miles or a little less in the working field.

yes

True and i have noticed that easily. There is a 5.4L Expedition at work and it has much better torque than my mother-in-law's 5.3L tahoe. I think the tahoe has very weak gears in it because it is constantly down shifting with just a little added throttle. I just noticed that the rpms wind in it and other chevy's i have driven more easily than the ford motors.

Even by buddies old 1998 Z71 350 back in high school would rev higher when accelerating with only moderate throttle. The fords i have driven just tend to push on accelerating but with less of an rpms range. Just a something i noticed when driving my mother in laws tahoe the other day.

It seems to me it could just be a function of gear ratio's.

WHAT??

my buddy has a 03' 5.4 liter triton that has 430k on the odo.

mainly high way miles and he doesn't tow but still that is impressive.

I want to get mine to 240k and I'll be happy

I dont know that is the reason, cause my truck has a 3.55 rear end with bigger tires so ultimately i have a ratio around 3.31 in the rear (after calculating the taller tires) and the 4.6L in my truck is far from a hp/torque machine. You would think the weaker motor with smaller gears would need to wind up more rpms to gain speed as a result of not having enough gearing but the exact opposite happens. Her 5.3L has more hp and torque with small gears and still revs more. A Z71 i drove with 3.73 gears shifts the same as the tahoe, shift points at higher rpm numbers than a ford motor at same level of throttle/acceleration.

my buddy has a 03' 5.4 liter triton that has 430k on the odo.

mainly high way miles and he doesn't tow but still that is impressive.

I want to get mine to 240k and I'll be happy [/quote]wow that is impressive. havent seen too many with that kind of miles. saw an expedition with almost 500k Christian truck is a 2000 2500 with a 6.0L and it has 360k and still runs like a champ. burns alittle oil, but not too bad. i took it on a 1500 mile trip and it didnt burn a drop. crazy

Not sure, but I think it has a lot to do with the gearing like someone else said. That Tahoe may/probably has 3.08 gears.

I noticed right off the bat when I got my chevy 5.3 about its downshifting. You practically cant give it the proper amount of gas to make it downshift from 6th to 5th gear. If you give it enough gas to downshift it will drop straight from 6th to 4th. If you really hammer it going down the raod it will drop from 6th straight to 3rd.

Also newer vehicles adjust to how you drive them, If you drive it like a granny it will try to drive like a granny upshift fast etc. If you have your foot in it 100% of the time it will downshift more readily etc.

Another example

In my 94 chevy 1500 if you put the pedal to the floor that thing would redline in a heartbeat. My mom had a 97 GMC Yukon, it easily had more hp and torque than my 94, but when you put the pedal to the floor it would never really get over 4-4500 rpm before it shifted with a redline at 6.

Funny; my last work ride was a F-250 with the 5.4. Powerwise it was a slug, but the thing wouldn't shift below 3k. The dealer said that was normal, and didn't understand why I questioned it. I hated the truck, but I will say that the engine never used a drop of oil. We ran 6k between changes with Mobil One synthetic, and it was always full or near full at 6k.

There are many variables that effect the way an engine responds to throttle input. Vehicle weight, gearing, wind resistance, are all part of the load on an engine.
Engine response to load is greatly effected by intake runner design, combustion chamber design, camshaft profile, connecting rod ratio, etc..
Here is a useful link that will help to explain how basic engine design greatly effects response of an engine.
http://victorylibrary.com/mopar/rod-tech-c.htm