What's your cruising RPM in 55 MPH zone?

[Kungfukendrixx]

Do you cruise in 5th gear or 6th gear when doing about 55-60 mph. I feel like the RMP are a bit too low to go to 6th gear, so I stay in 5th and keep the RPM's at about 2000-2200. I don't like my RPM's to drop below 1800 at all, does't feel right to me. Curious to see what others think is a good cruising MPH and RPM in a 55 MPH zone when actually doing the speed limit and not speeding.

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[tom_sprecher]

If I'm doing 55-60 mph it's because the speed limit is 45, and 5th gear is fine since I might have to let off a bit for blind apex turns, side roads and driveways. 6th gear is too low revs.

 

[Kungfukendrixx]

I typically do about 10 mph over the posted speed limit as well, but not on this highway. It's a speed trap.

 

[Zelek]

6th gear is fine as long as it's flat or downhill with a good stretch of road. Downshift to 5th up hills. I've even done 6th gear up light hills at 50-55 and it doesn't lug. I've got 3.73 gears though so I'm sure that makes a difference.

 

[Kungfukendrixx]

6th gear is fine as long as it's flat or downhill with a good stretch of road. Downshift to 5th up hills. I've even done 6th gear up light hills at 50-55 and it doesn't lug. I've got 3.73 gears though so I'm sure that makes a difference.

I have 3.73 gears too. I just seem to never use 6th gear unless I am on the interstate, doing above 65 mph.

 

[Zelek]

I have 3.73 gears too. I just seem to never use 6th gear unless I am on the interstate, doing above 65 mph.

5th is usually good to about that range you listed if your goal is just regular, normal driving and more efficiency. It all really depends on the stretch of road and if it's flat / no traffic. That would be the determining factor to cruise in 6th or have more power available in 5th. Nothing wrong with either.

 

[tom_sprecher]

I have 3.73 gears too. I just seem to never use 6th gear unless I am on the interstate, doing above 65 mph.

Same here. Can't image having 3:55 or 3:31. Seems like you would have to be doing 70 or better.

 

[scotty]

Yeah, I have 3.31 rear end gears... I won't use 6th until I'm around 110-120km/h and only as a cruising gear.

 

[Rock&Roll]

3.31 gears here. 6th gear is only good on the NYS Thruway.

 

[jimmerheck]

2nd gear, near redline. Everywhere. You do mean rental cars, right? Oh, you mean MY car. Mine gets driven in 6th at 55, 3.31 gears.

 

[WildHorse]

Mine gets driven in 6th at 55, 3.31 gears

Same 1100ish RPM.

 

[NightmareMoon]

I can't drive 55.

 

[CAL Captain]

I know I'm going to get nailed someday but my normal 12-mile jaunt up 101 from Pismo Beach to San Luis Obispo is usually conducted between 75 and 95.

So, 5th for 55-75, 6th after that.

 

[GregP27]

I wrote a calculator in Excel, but you have to KNOW your gears ratios and tire diameter.

For reference, my 2019 GT is due in Feb 25, and I have wheels and tires waiting. I chose 285/35ZR19. The diameter is 26.850". My car is a 6-speed, and I have all the gear ratios for the stock GT.

At 60 mph, in 6th gear, it will be turning 1,973 rpm. That seems OK to me. I suppose I'll see when it gets here if that is enough rpm for the smaller displacement engine (smaller than an GM LS1, anyway).

My last pony car was a 2002 Camaro SS, 6-speed. It came stock with 3.42 gears. At 60 mph in 6th gear, it was turning 1,339 rpm and was not useful until above 70 mph. When the rear end went bad, I went to 3.73 gears, and the rpm at 60 mph went to 1,460. I used it at about 65 mph. Worked fine unless I needed to accelerate quickly.

Cheers.

 

[5OhSilver]

OP has an 18 GT with the MT82D4. The gears are longer than the mt82 in the 15-17, so even though you both have 3.73's it won't be the same RPM at a certain speed. I have a 15 GT PP and at 55mph I tend to stay in 5th until 65ish as 6th gear gives too low revs at anything below that speed imo.

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