Top Speed, 6th Gear & What were they thinking?

I have to agree, 5th gear is plenty for any high speed driving. It's nice to be able to cruise and get some decent MPG's in 6th gear during long drives.

Based on my analysis, in order to get into the fat part of the torque curve (3500rpm and up) in 6th, you'd have to be going ~120mph. In 5th, when you hit the fat part of the curve, you are only going ~75mph. Your torque is on tap at 75mph in 5th, making it feel much more responsive. If you are doing 75mph in 6th (~2200rpm), you lose ~160 lb-ft of torque at the wheels, due to the shape of the torque curve and gear ratio disadvantage (of being in 6th vs. 5th).

Hence, 6th is for cruising only - you'll need to drop down a gear to get a move on...

Mike02z said:

You still pay a gas guzzler tax on the GT350 and Ford does not even use a skip-shift to improve mileage. I remember trying to pass people on a highway in 6th and it was impossible. I always had to down shift into 5th. This is likely more to do with where the power band is on the GT350 and less about fuel economy.

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I am so glad that there isn't a skip-shift in this car. Both my C5 and C6 Z06's had them and it was the most annoying feature ever. It was the first thing to be disabled.

I'm fine with 6th gear being as long as it is. I just leave it in 5th on most surface streets and get good highway economy. On two highway trips to autocross events I was averaging over 25mpg at 70ish mph, which is way better than the EPA estimate.

GT_Dave said:

The GT350 will do close to 170 MPH in 5th gear.

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It will do more than that. I was hitting high 180's maybe low 190's (can not remember for sure) in 5th at the Texas Mile. We were having tune issues and the car was hitting a wall at about 8000RPM, if it weren't for the tune it would have done more than that in fifth. It just quit revving.

Well I have always used 6th gear for cruising along. If I wanted to pass I have always dropped down in gear, I did this in my 11 Shelby. 6th was like a drag on the clutch to try to pass people in. Case in point, this morning I needed to get around a trunk I suspect was carrying gravel and I was cruising in 6th at about 80...Drop to 4th and shot around it like whoa......So I like the 6th gear as it stands.

Don't forget that the better mileage in 6th also helps with the CAFE standards for a manufacturer. A couple extra miles per gallon can make a big difference in the grand scheme of things for the entire fleet.

Also, a 6th gear that was only slightly taller than 5th gear would not be used at the track anyways. It would be useless since you wouldn't be grabbing it until 150 to 160 MPH. It only makes sense to have 6th as a tall gear.

CaptainUnderpants said:

I just got back from a 1,550 mile round trip to Telluride, CO and back . . .

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We must have just missed you. We left there on June 30th, after a fantastic week away from the Dallas heat. That would have been way cool to see a GT350 up there! Were you in town, or mountain village?

sublime1996525 said:

I am so glad that there isn't a skip-shift in this car. Both my C5 and C6 Z06's had them and it was the most annoying feature ever. It was the first thing to be disabled.

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I didn't say I like them. I'm just saying if Ford wanted the GT350 to get better mileage they should have used one. Not like anyone will miss the 25 bucks to get the eliminator. If you have driven multiple cars with this you likely don't even need the eliminator. My HC has one and I have never had it put me in 4th. Yet my son had to get the skip shift eliminator for his HC as he hit it all the time.

MrCincinnati said:

Much love for the fellow Mopar owners here... however c'mon man if you couldn't pass someone in 6th it's because they didn't want you to pass them.. and at that point it's a race

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Same love right back for my Ford friends I'm manufacturer agnostic

I think most GT350 drivers will admit, there is no one home below 3500 RPM in the GT350. I thought 6th was fine for the highway. I just know whenever I needed to pass on a highway, I needed to drop into 5th or 4th. I didn't have any issue with that. Maybe I like passing faster than most, but when I floored the car in 6th, very little acceleration.

GT_Dave said:

The GT350 will do close to 170 MPH in 5th gear. There isn't a track in the US that will allow you to go that fast in stock trim and the car doesn't have the power to go much faster under any circumstances. So if I were a Ford engineer, why not utilize a gear that would provide better fuel economy. For those of us that DD our GT350's, I'm fine with 6th gear the way it is.

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Daytona ;)

And I am fine with 6th being tall for cruising to get better gas mileage and less wear and tear on the engine.

Peter

torque124 said:

keeps the wife happy

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.....and the base/tech pack trans as well ! ;)

No issue with 6th, its a true over-drive gear as intended. 5th is already 1:1 so a slightly "taller" 6th really would not yield a whole lot of extra umph anywa, especially with how broad the power band is. If you want to pass, drop a gear (or two) and open those valves up.

oldmachguy said:

We must have just missed you. We left there on June 30th, after a fantastic week away from the Dallas heat. That would have been way cool to see a GT350 up there! Were you in town, or mountain village?

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I was also in CO this last week; I saw two GT350's. One in Idaho Springs (white w/ blue stripes) and one going over Berthoud Pass (black).

MrCincinnati said:

Also - and feel free to flame on - Who is running this thing to 170 anyway? Where?

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Mexico ... FTW :cheers:

Yes, in Mexico I got mine up to 151 mph in 5th but then saw a Federally and decided to slow her down. The car had plenty left.