what are the maximum speeds you can go in each gear on a 5 spd? I'm not talking about maximum downshift speeds. I'm talking about can I go 80mph in 4th gear? I don't have a tachometer so I have no idea if I'm close to redlining other than by the sound of the engine. I drive up steep hills a lot and I have to be in 4th or 3rd to get up them, but I'm afraid to drive faster than 60 mph in 4th even though I want to to keep up with traffic.

Also, when I need to accelerate hard to merge onto the freeway or something, I want to leave it in each gear as long as possible. It's tough to know when to shift without a tach, though. I usually take it to 20mph in 1st, 30 in 2nd, 40 in 3rd, 55 in 4th, and then 5th.

When going up mountains, I'm in 4th the whole time going about 55mph. Is this alright for the engine? Can I push it to 65 mph, even 75 in 4th?

 

This is my experence: I can get 30 in first, 50 in second, 80 in third, and max out at 97 in fourth at the speed limiter! This is shifting at 5000rpm with engine cut off at 5200rpm. I have no problem at all of grabbing third gear at 65mph and jumping on it!! This is on my truck and yours might be different. This is at max rpm and also an example of what MY 4.6 can do!

 

icetruck, what year is your truck? there is a secret tach in the digital odometer, I think from 2000 and newer. It may even be on the earlier ones.

also what engine and rear diff gears do you have?

Jeff51, thanks for the info!

 

radar, forgot to put in my sig! My truck's info is there.

jeff51, that sounds pretty crazy. I'd be afraid to shift like that but it's nice to know I could. Really? 97mph in 4th? Cool.

Thanks to both of you. I don't have an electronic odometer so the secret tach route is out for me.

 

With a chip to remove the speed limiter and bump up the rev limiter (to something like 5700) I have hit the rev limiter at 91mph in third (at the track). I would guess fourth is good to 110-115 and fith as fast as it'll go before hitting the areo-brick wall, I'm guessing somewhere around 130. The exact numbers are tough to figure out with a 100mph speedometer

Without a chip I would hit the speed limiter at 95mph in fith. The rev limiter (set at 5400) would shut it down in the lower gears.

One thing to keep in mind is that the speed limiter is there to keep us from exceeding the speed rating of the tires. My truck has got the get-up and go to exceede the speed rating of the tires so I don't speed for more than a short stint and the bring it back down to a more reasonable speed.

 

Believe me I don't even want to approach the speed limiter. Not really a racer or anything like that. My truck works, get's me from one place to another and goes off-roading with me. I rarely want to even hit 80.

Thanks Wittom for the info that helps. So I guess that means I can pretty much cruise in 3rd and 4th all day when I'm going through the mountains. That's what I wanted to know, if I could stay in 4th and go 70 - 80 mph uphill.

It really sucks not having a tach. When I get some spare cash I'll put one in.

 

Do you have the digital odometer in your 98 or is that a 99 and up thing?

if you have the digital odometer, you do have a tach....

 

nope, my 98 has the old fashioned analog odometer. too bad.

 

icetruck,

I have the same drivetrain as you. I would guess Jeff51 has the same too. I don't have a regular tach, but I have the digital odo tach. I don't think I've ever taken it above 4000 YET, but my math from my observations at lower speeds / rpm's comes out to about the same as Jeff51's actual numbers.

Lately I have been driving in 4th a lot more. I commute on a stretch of road where the speed keeps changing up and down from 40 to 65 mph. I have been just leaving it in 4th instead of shifting up and down. 65 in 4th is only about 2600 rpm, it could run all day at that no problem. Even with the 3.55, 5th is too high. I only use it if I'm going to be doing 60 - 75 mph for a while (interstate).

I guess you can safely run these engines right up to the rev limiter frequently with no excessive wear. Mine sounds and feels fine revving up to about 4000, and it makes good power up there, I am just not used to revving any higher, YET!

 

hey thanks radar_ridr

That's exactly what I wanted to know. Not having a tach always had me second guessing whether I was wearing my engine out. Guess I never even approached redlining or anything like that. Cool. Can't wait to power up those hills!