High RPMs at low speeds - 2011 GT
 

I've had my car for three weeks, and I've done mostly city driving - traffic light to traffic light, unfortunately. So I haven't been out on the open road yet to really test the car's abilities, something I hope to do soon.

What I have noticed is that at low speeds, in traffic, the car seems very uncomfortable unless I shift quite early to the highest gears. The RPMs are higher than I'd expect, making me wonder if the engine is working too hard. For instance, say I'm at 40 MPH in 4th gear - the RPMs tend to be between 2,500 and 3,000, making me feel like I need to shift to 5th.

Even at 50 MPH in 5th, the RPMs are well above 2,000, and I find I have to shift to 6th. Typically, in
6th gear, the RPMs fall back to just below 2,000 but by the time I'm up to 60, RPMs are climbing back toward 3,000. Makes me wonder what the RPMs would be at 70 or 80 if I ever get the chance to go that fast. There's no 7th gear, obviously.

Is this normal? I'd like the engine to be under less strain in normal driving. I think it's a bit strange to be driving in 6th gear at 45 MPH, though I know other posters here have said they do this. If I have a complaint about the car, it's that it never seems really comfortable in 3rd and 4th gear, even at speeds I feel are appropriate for those gears. I'm doing a heck of a lot more shifting than I'd like to do (I have a 10-mile commute and in that commute face 10 traffic lights - yes - it's hell.

Something doesn't add up.

70 mph in 6th should be about or under 2000 with 3.55 gears.

But you should always use the highest gear you can to for the speed you want to cruise at.

I can puddle around in 5th in my '04 at about 1200 rpm and 45 mph.

since it's now a six speed gearbox, Ford added and extra-low 1st gear. So when you would have been in 3rd previously, you should now be in 4th, etc.

I'm assuming you have 3.73s? According to charts, 70 mph = 2111 rpm.

Yes, that's normal, the car is geared almost absurdly low, deeper than the Camaro certainly. Gears aren't too complicated, there's a 1:1 relation between your speed and RPM in a given gear, and that really won't change, it's all mechanical with a bunch of wheels spinning each other. The gearing is what determines the relation between RPM and speed. This relation should never change, unless your transmission explodes, arguably if your tires break traction but I tend to think more in terms of X RPM means tires are spinning Y fast.

You noticed the big drop going from 5th to 6th, and that's also normal. Most of the gears are roughly 3/4ths of the gear before it, but 6th is 0.65:1 while 5th is 1:1, it's a steeper change, less than 2/3rds what 5th is.

I have 3.73s and I'm in 6th usually at 45 MPH. And yeah, I'm in the 2000s going 75. It's normal.

Also, he has 3.55s from his signature.

Thanks. What difference would I notice if I had opted for 3.31? When I bought the car, I didn't consider that having a 3.55 would mean going into 4th at 30 MPH.

So do you recommend starting in second and just ignore 1st? Then I can treat third like second and so on.

Not huge, most of it is in the gearbox, and the difference between 3.55 and 3.31 isn't huge. 30 MPH in 3.55s at whatever RPM is a little over 32 MPH at that same RPM in 3.31s.

I've actually started in third before and thought it seemed a little uncharacteristically sluggish before I realized it was in 3rd. I've even accidentally started in 4th before, though I wouldn't recommend that. A number of people actually start in 2nd most of the time, I generally prefer to start in 1st, but I don't mind going through gears.

Here is a speed in gear chart for a regular GT with 3.55's. Looks like you should be in 5th at 40, 70 in 6th is 2000.

http://haloclub.com/albums/album02/G...gear_chart.jpg

When I'm just poking around town I will often go 1-3-5. With the 3.31 axle, the car is very comfortable being in 5th gear even at only 30-40 mph.

Good tip right there. Don't worry about the RPMs, skip gears if you're shifting too much, just go by the feel of the car.

The Coyote is an engine that doesn't mind being in high rpm, so I wouldn't worry about over working the engine. Unless you are trying to get the best MPG. Like others have posted it is OK to skip gears or start out in 2nd. I start out in 2nd 60% of the time in the city. 1-3-5 is also very comfortable to me.

I'm not worried about mileage, only concerned that I'm overworking the engine by always being up near 3,000. Also, the engine seems kind of noisy at that point, like it's begging me to shift, which is annoying. I guess the solution is spend more time in 5th gear even when I'm not on a highway. It's just hard to make such an adjustment in my mind after nearly 25 years of driving manuals and only using 5th when I was on the interstate.

Never used 5th before on streets? In my 07 GT I cruise around the streets 45-50 mph in 5th gear all day long.

Did those cars even have a 6th gear? When I'm on the interstate I don't use any gear but 6th.

btw it's never a good idea to lug your car around lower than it wants.
lugging, overloading your engine in too high of a gear is not good.

I agree with that. In normal driving I shift right around 3K RPM with light pedal pressure (so light that it wouldn't rev beyond 3000). I don't know if this is the correct shift point, but it feels like this is less stressful on the engine than shifting at 2K RPM and then lugging it around 1K RPM. I also never hit the 1-4 skip shift.

Am I wrong?

Depending on how much acceleration I need, I generally shift between 2.25 and 3k. The engine likes to rev, so I doubt you're hurting it by revving to 3k before you shift. Granted I put the clutch to the floor every time I shift anyway. Really, with my car, when I get it up to 3k I think it's less saying "Less revving! Shift up!" and more saying "Go FASTER! FASTER!!"

Then again though I get bothered by the skip shift on occasion. I generally consider 1.25k and below to be close enough to lugging to justify shifting. Even if 1st I don't let it drop below 1k RPM.

I recently began starting in 2nd.....not because of rpm but because I dont have to shift on the way to 60mph. Not sure if its faster then starting in first bit it feels like it!

The gears I use the most are 2nd and 6th. Always start in second(even on hills) and then when I hit 60, it goes to 6th. Around town it is 2,4,5.