My 2002, 4.7 V8 idles at close to 2000 alot. Sometimes I get it around 1500 or a little lower on the highway. Too high isn't it? Very hard on gas too. How can I get a lower rpm?

 

adjust your timeing or your idel speed

 

MQ:

Both your timing and the idle speed are set by the computer. You can not adjust them.

I imagine your throttle body is dirty, and possibly the IAC as well. Running the rpms that high all the time is not good, and no doubt when you shift the tranny into gear it must jump.

You will want to fix this for econcomy as well as safety reasons.

Don

 

idle in park should be about 500 rpms, and cruise on the highway is btwn 1500-2000 rpms btwn 55-75 mph this is what i run w/ 4.7 v8 5sp auto tranny and 4x4 w/ 3.55 rear and i agree check IAC and replace if it does not move freely, and clean the throttle body

 

If you are going down the highway, you are not at idle unless you throw the tranny into neutral. It sounds like you are talking about cruiserpm instead of idle rpm.1500 rpm cruise speed on the highway is very low and is about optimum for gas mileage. (Any lower and you are really bogging the motor and would either have the tranny hunting for gears all the time or using more gas if it stayed in that gear.)

 

Yes, when I'm driving it runs close to 2000, not idling. Even in-town driving, it runs over 1500 rpm. It almost seems like I have to get the speed up then let off the gas for the rpm to drop below the 1500 mark. It takes alot of gas! It has over drive too, which I usually leave it in. I suppose in-town driving would be better with over drive off?

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you ahve almost the same truck as i do normally around town rpms are btwn 1500 and 2000 thats normal, idk what your mpgs are, but were i am i get about 14 in town and 20+ on the highway these things are NOT good on gas, and most of us do not have them to try and save gas, we generally dont care and drive what we want to regardless of gas

and depending on what you consider in-town driving yes turn od off it saves the transmission bc of less shifting and it seems to take a little more pedal to make it downshift uphill(at least mine does)

my .02

 

I don't know what you're expecting. Most cars rev much more than that driving around town. The only reason that the D revs so low is that it is a V8 and has more torque than most vehicles. My other car is a Infiniti J30 and just normal driving around town the motor revs to 4k rpms.

Why do you think you need the engine to drop below 1500 rpms while driving? 1500 rpms is very low.

 

MQ:

I don't know what you are used to driving, but our Durangos weigh close to 5000 pounds. It does take abit of oomph to get them moving. What you have described for your D seems pretty normal. Around town my D with its 3.55 gears runs in the 1.5-2k range. If I push it a bit, it will shift around 3-3.5k. WOT shifts are around 5.3k.

Smaller engines cannot produce enough torque at low rpms to do the job, so they are geared to run faster at a given speed to get the job done.

Don

 

I concurr, mine is about 800 rpm COLD500 warm. I am in the process of making a excel spreadsheet for these very issues.
It will be at idle. and a various speeds both warm and cold. I run about 2000 rpms warm at 70MPH with A/C on and full electrical
load (radio, lighting, A/C, cell charger, GPS etc..) Once in I will post results.