RPM

[rjr]

Can someone with a new 07 please tell me what RPMs in 4th at 45 or 60? Given that the 6-speed has no direct drive, I'd like to compare RPM with OD locked out to my current 4-speed Expedition w/ 3.3 axle.

[ELlover]

Can someone with a new 07 please tell me what RPMs in 4th at 45 or 60? Given that the 6-speed has no direct drive, I'd like to compare RPM with OD locked out to my current 4-speed Expedition w/ 3.3 axle.

 

 

When I go out later, I will do it for you. I'm not sure when I will write back but I will do it.

[ExpyBob]

At 80MPH it's a hair over 2000rpms.

 

Bob

[Radcad]

Hey RJR -

 

While driving today in my '07 I took the readings you asked for:

 

O/D off - 4th gear at 45 mph = 2,000 rpms

O/D off - 4th gear at 60 mph = 2,650 rpms

 

Hope that helps.

[rjr]

Thank you both. Reason I ask is that the wife & I do a lot of mountain driving. We've gone from our home in VA to the west coast 6 or 7 timnes in our 97, and do a lot of driving in the Appachians. If we leave it in OD, there's too much shifting as you go through areas where the terrain is rolling, so I often will leave OD locked out. These RPMs that you report with OD locked out seem considerably higher than in the 97, which has the 3.31 optional axle.

 

I was also surprised when I did a few calculations, and found that 1st on the 07 is a 17:1 overall ratio, compared with slightly over 7:1 on the 97. That's a real stump puiller, & I can't see the purpose of it.

[ELlover]

Sorry I didnt get back to you sooner but I see that RadCad answered for you. I got 2000 RPM's at 45 on a flat road and up hill holding steady at 45 was about 2250 RPM's. At 60 MPH i got 2850 RPM's on flat and almost 3000RPM's on a slight hill. I wonder why mine would be higher than RadCad's? I will check again when I go back out later.

[rjr]

Sounds like your transmission torque converter may not be locking up. Worth checking into. If driving above say 50, with engine pulling, and you step on gas slightly (w/o causing a downshift), RPM should not jump up.

[ELlover]

Sounds like your transmission torque converter may not be locking up. Worth checking into. If driving above say 50, with engine pulling, and you step on gas slightly (w/o causing a downshift), RPM should not jump up.

 

I will have my husband drive it tonight to see, he is more mechanically inclined then I am. We have had the EL for almost a month now and he still hasnt driven it so this is a good reason to force him. I will post back.

[Radcad]

Tiffany

 

When I checked the rpms in 4th gear I was on flat, level ground and had the cruise control set both at 45, then at 60. Even the slightest hill would make the rpms rise, I noticed.

 

rjr- doesn't it make sense that the '07 with O/D off, in 4th gear would have higher rpms than your '97? Is that trans a 4 speed? I would think that all the gear ratios on your '97 would be higher because of less gears? Just curious - I don't know that much about axle ratios. And wow 17:1 1st gear! Is that right? That IS nuts. Who would need that much torque down so low?

[rjr]

Tiffany

 

When I checked the rpms in 4th gear I was on flat, level ground and had the cruise control set both at 45, then at 60. Even the slightest hill would make the rpms rise, I noticed.

 

rjr- doesn't it make sense that the '07 with O/D off, in 4th gear would have higher rpms than your '97? Is that trans a 4 speed? I would think that all the gear ratios on your '97 would be higher because of less gears? Just curious - I don't know that much about axle ratios. And wow 17:1 1st gear! Is that right? That IS nuts. Who would need that much torque down so low?

According to the 07 specs, 4th has a 1.14:1 reduction. The 97 4-spd is 1:1 in 3rd (OD locked out). Multiply this times the rear axle ratio, which is 3.73:1 on the 07 and 3.31 on my '97 (I have the optional axle), to get the overall ratio. There is a slight adjustment because of the different wheel sizes, 17" vs 16", but overall, the result is that there is a substantial differnce in RPMs with the OD locked out.

 

For info, 07 specs give the following:

1st 4.17:1

2nd 2.34:1

3rd 1.52:1

4th 1.14:1

5th 0.86:1

6th 0.69:1

REV 3.40:1

 

The 17:1 figure in my post is an arithmetic error; it should be 15.55:1, which is still a stump puller. The 07 spec sheet shows 1st has a 4:17:1 ratio. Multiply that times the 3.73:1 axle and you get 15.55:1. By contrast, the E40D in my 97 has a 2.71:1 ratio, yielding 8.97:1 overall, which I have found to be quite adequate. (When I did have to pull a stump, I used 4L).

 

I am surprised to now hear 2 people say the RPM jumps when they step on the gas. Does the 6-speed shift so easily from 6th to 5th?

[Radcad]

RJR-

 

I had O/D locked out, in 4th, when I referenced that the rpms would rise on a hill. The trans wasn't downshifting, I was just suggesting to ELlover that her reading of 2850 isn't really that much of an anomaly compared to my reading of 2650 - depending on how much pressure she had on the gas pedal.

 

When driving into down last night I had the trans in "D" with the O/D on. I set the cruise control at 45, and the trans stayed in 6th gear even up small rises in the road - this at 1250 rpms. So, no I don't think the trans shifts too quickly from 6th down to 5th or 4th. I have drivien my sister's car (a Jaguar X-type) with a transmission that's WAY too quick to downshift, and it's incredibly annoying. But the Expy is not like that at all.

 

Have you had a chance to test drive the '07 Expy?

[rjr]

No I haven't driven the 07. I'm not in the market until April, because (1) I try not to buy a car that's had substntail revision unti the initial bugs have been resolved, (2) I'll be spending much time in a large northeatern city on business, wiith the vehicle left alone in a public garage for weeks, (3) the delaers here are only getting limiteds and eddie bauers with leather seats, & I want to see the XLT with cloth. Besides, I only have 183,000 miles on the 97. So I see no need to excite the dealer

[Radcad]

Rj

 

 

I laughed out loud at your comment: "I see no need to excite the dealer"...it doesn't take much to do that, does it? I asked about you having test drove the '07 because I think you will see a substantial improvement in the ride. Even with the 20" wheels it's impressive.

 

By the way, do the 20" wheels mess with the final overall ratio? I noticed you mentioned 16" or 17" wheels when doing your calculations.

 

BTW, any problems with your '97 with 183,000 miles?

[rjr]

The tire outside diameter does have an effect. While the ratio does not change, the circumference of the tire, which is 3.14 times the diameter determines how far the car will move with one turn of the wheel. If the larger diameter wheel is used with tires having a different aspect ratio, it is possible that the ditance per revolution will not change. The speedometer is set up according to the tires/wheels on the car when manufactured.

 

The only problem I had with the 97 was with the front brake rotors warping, & since 160,000 miles I have replaced 4 ignotion coils. I eventually gave up on Ford rotors and installed rotors with round vent holes through the braking surface. This solved the problem. The 5.4 enigine has had nothing but Mobil 1 10-30 since I took delivery, & I have changed the transmision oil (16 qts) & filter in the E4OD every 25-30,000 miles. One thing about this trans is that there is a plug to drain the torque converter, which helps. Has crossed the US 6-7 times, including off-roading in the west.

Edited November 5, 2006 by rjr