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65 Mph And Rpm Question


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Hi there, maybe I am losing my mind but what are you guys and gals seeing the rpm's at going 65mph. I have stock 235-70-15 tire size. I am seeing anywhere from 2600 to 3000. It seems that when I start driving on the highway for the first time that day I am at 3000 rpm for a good bit then it drops to 2600 or so. I don't remember it doing it in the past and just want to catch something early if something is going wrong. There are no strange noises and everything seems to be working properly. Maybe it is just an age thing, 122k and 97 model

 

Thanks

James

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If it is cold where you are, it could just be that the tranny has to warm up before going into full overdrive. I know mine does the same thing. After a few minutes on the highway it locks the torque converter.

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i dont have the same year as you mine is a 94... but i have the same problem in the morning my truck wont use overdrive until the trucks warms up, so i use alot of gas and im right beside the hwy.... i just drive slower untils its able to shift into overdrive. which isnt to long

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Good deal, it sounds like not a big deal. My overdrive works, if I turn it off at 65 it goes to something like 4200 so I guess it is just the warm up and needing the converter to lock up. I just need to be less picky :) and not notice the every little creak and noise in an older vehicle.

 

James

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When you first start your truck (cold) the engine operates in "open loop mode" This bypasses readings from the O2 sensor and the engine runs rich to help it warm up. During this time the automatic transmission's lock-up torque convertor will not lock up. This causes higher RPMs. Once the engine reaches the correct operating temperature the O2 sensors come on line and lean out the mixture and the torque convertor locks up which drops the RPM a bit (feeling like a shift into OD). This allows the engine to warm up and the truck to go down the road in the best manner possible until things are warmed up.

 

If the warm up period is taking longer than it used to, it could be:

Very cold outside

Thermostat stuck partially open (most common in my experience) or incorrect thermostat

engine temperature sensor malfunction

 

HTH

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Yery good lesson on the cooling system BowTied. I did just have the Timing belt and water pump replaced so maybe something with the thermostat is goofed when the system was drained or maybe it could be air in the lines? I will work them out tonight to rule that out. It has been a constant cold here latlely but nothing to super cold.

 

Thanks All

James

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  • 2 years later...

As my manual say "The over drive does not engage until the engine has warmed up" Mine used to worry my till I realised it knows what it's doing. Once it engages I'm at 2000rpm's at 90 KMS.

Edited by kdj
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The 4th gear in Pathfinders are, in my opinion, have too low of a ratio. At 65mph my RPMs are running around 2400 rpm. For highway cruising the RPMs should be around 2000. That would help a lot for highway gas mileage and easier on the engine and trans. My past several vehicles (1998 to 2005 model years) with V-6's all have ran around 2000 RPM at 65mph. Just seems like when I run 70mph that it just feels like it needs another gear to change to. 2005 model year went to 5 speeds with a higher 5th gear ratio from what I hear. But those transmissions are flawed too and are going out left and right.

Edited by lzrj
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The 4th gear in Pathfinders are, in my opinion, have too low of a ratio. At 65mph my RPMs are running around 2400 rpm. For highway cruising the RPMs should be around 2000.

 

I don't think the 3.3 V6 has the balls to pull it along at 65mph @ 2000rpm.

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We are talking about different engines too. I just saw that the OP has a 97 with 3.3L and not the 3.5L. Mine has the 3.5L which is why it may do about 200 less rpm at that speed with is not much difference with a more powerful engine. Either way, any V6 should not have the be revving that high for highway cruising speed.

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Either way, any V6 should not have the be revving that high for highway cruising speed.

 

The VG33 is:

Reliable

Physically small

Lightweight (for what it is)

Reliable (again)

 

The VG33 is not:

Quiet

Torquey

Powerful

Refined

Simple to repair

 

We probably need around 90 horse to do 65mph and still be able to do anything like go up a hill or accelerate. At 2000 RPM, I think the VG33 is only good for about 75.

Edited by pathfounder
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Just for fun today after I put my new Iridium IX plugs in, I went for a little cruise (it actually wasn't that fun). Just for your comparison, mine is revving 2200-2250 at 100km/hr (62mph) locked the cruise control on and it was flat for a couple clicks. When is the USA going to join the rest of the world in metric ;)

 

Imperial MPG, US MPG, L/100KM, KM/L. Let's standardize this stuff!

 

Should add thats on 245/75/16's

Edited by dynomax
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Imperial MPG, US MPG, L/100KM, KM/L. Let's standardize this stuff!

 

The only ones that make sense to me is distance over fuel volume. The L/100km thing is just silly.

 

5L/100km = amazing.

10L/100km = poor.

 

You have to get into decimals to compare minor differences. Also, it is a "less is more" kind of thing which doesn't make sense to me in this case.

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The only ones that make sense to me is distance over fuel volume. The L/100km thing is just silly.

 

5L/100km = amazing.

10L/100km = poor.

 

You have to get into decimals to compare minor differences. Also, it is a "less is more" kind of thing which doesn't make sense to me in this case.

 

10L/100KM is actually not poor, its 28 Imp. MPG/24 USMPG, 20L/100KM is 14 Imp MPG/12 USMPG. No pathfinder here gets that :)

 

20L/100KM makes sense to me, its just the inverse of what you think is normal, miles per unit. I am Canadian, and grew up in Metric, so it makes sense to me, and all canadian vehicles with the onboard economy measure use L/100KM

Edited by dynomax
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Easy conversion:

 

US MPG = 235 ÷ E

 

E = The rating /100kms in metric. So, for instance, 10L/100KM

 

235 ÷ 10 = 23.5mpg

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The 4th gear in Pathfinders are, in my opinion, have too low of a ratio. At 65mph my RPMs are running around 2400 rpm. For highway cruising the RPMs should be around 2000. That would help a lot for highway gas mileage and easier on the engine and trans. My past several vehicles (1998 to 2005 model years) with V-6's all have ran around 2000 RPM at 65mph. Just seems like when I run 70mph that it just feels like it needs another gear to change to. 2005 model year went to 5 speeds with a higher 5th gear ratio from what I hear. But those transmissions are flawed too and are going out left and right.

at 65 that RPM seems high. If i am cruising at 60 (which is actually 65 due to my speedo reading faster then it actually is) i am right at 2000 rpm. I find it weird that there is such a difference in rpm with others that have the 3.5 engine

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mine runs that high too. all the time, it doesnt drop. at 70 im running bout 31-32 k

 

You must be getting a gallon to the mile.

 

It's either not in 4th, or the converter clutch is never engaging, or you have couch casters for wheels.

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Or he has a manual. My dads old 2000 r50 with the vg33 and a 5 speed was just at 3k at 110km/h. It actually got around 20mpg on the hwy even with the stock hubs.

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