Gear Selection when Cruising at 50mph

[Average Jae]

i have a six speed manual 330i, and when i first got it, i used to put it into the over drive 6th when cruising the local roads around 45 to 50mph. the rpm sits around 17, 18 hundred, and it seems a bit low for my taste, esp when i try to adjust the speed up a bit. so i just started using my 5th gear to drive around town and use my 6th for highway driving. i still get pretty descent milage on 5th, so i'm wondering if i'll get couple more miles to the gallon w/ the 6th or not.

i believe the ratio on the 5th gear on my car is the same if not really close to the 5th gear on 5 speed manuals. i was just wondering what gear you guys coast around in, esp if you have a 6 speed box, ie 04 330ci, 330i or 03 330i pp owners. thanks

 

[codex57]

I coast in "D" What RPMs is it at when you're in 5th? If it's not much more than what you're getting in 6th, I doubt it will affect the gas mileage much. I'm sorta anal about gas mileage so I'd leave it in 6th. If you want more power, just downshift. The manual shifts so nicely that it's more fun than a pain. Enjoy that 6 speed!

 

[bmwrocks]

I also coast in "D". Sometimes in "S". Just love the sport mode of the Steptronic. It keeps the RPMs up over 2K constantly so the power is available when you need it.

The torque curve is so flat on BMWs that I am sure if you are not driving aggressively, cruising in overdrive at 50 MPH is fine. You can always downshift as needed for the extra boost. As long as you are not bogging down the engine at low RPMs in OD, you are not harming the drivetrain.

It is a matter of personal taste and how much you are concerned about mpg.

I used to own a 6 speed Trans Am which also had an incredible amount of low end torque. I would not use 6th gear except on the highway above 55 or 60 mph, to get the advertised mpg.

 

[Tom]

I rarely take my car up to 6th gear unless I go onto the freeway. 45-50mph, I still leave it in 5th gear.

 

[JamieD22]

Usually in 4th if cruising at around 45-55, 5th gear is reserved for highway use or wide open roads.

 

[flashinthepan]

I dont use 6th unless I am over 60 MPH.

 

[Average Jae]

thanks for the inputs and thanks for the D comment
should've made a poll or something ah well..

 

[epj3]

I rarely take my car up to 6th gear unless I go onto the freeway. 45-50mph, I still leave it in 5th gear.

You can go 45 - 50 mph?!?


It must drive you nuts...

 

[bcoleman]

I end up using 3rd a great deal of the time. I really like having the power to instantly shoot out of trouble (and driving in NYC and Long Island there are plenty of surprises that you need to avoid). When I am in third going 50 the RPMS are generally around 3500-4000. The engine is so quite it does not feel strained. Will this wear out my engine prematurely?

(I have an engineering degree and I studied some about engines and how they wear so it seams feasible that if the engine parts were not over designed enough, then faster wear would seam inevitable. If anyone wants the short technical description on why parts wear out and break, just ask).

 

[MrElussive]

bcoleman, you should probably go to 4th or 5th when you are relaxing. Staying in 3rd won't do anything, but why waste all that gas and put that much stress on the transmission when you don't need to, ya know?
As for the speed thing, I don't have a BMW but my car is a 6-speed manual and I only put it in sixth above 60mph. The thing is, it's not always better gas mileage to keep the car at the lowest rpm's possible, especially in this case. When you are going 45-50mph, you will get worse gas mileage when you accelerate if you are in 6th gear than in 5th. This is because the engine has to work much harder to power the heavier gear, and 5th gear makes the engine spin only 500rpm's faster but it is such an easier gear your engine will have an easier time with it. Basically, my advice is to usually keep your engine in the low 2K-rpm-range when cruising on the highway.

 

[Average Jae]

ditto mr g35 coupe driver. that's why i stared not going down to sixth gear.. i dun think keeping it on 3rd is a good idea, at least a 4th for bcoleman.

btw, i was sooo close to picking up a g35 six speed. then i decided to spend more money to get a bimmer.. only if the dealer didn't have the side mirror hanging off the car i was going ot buy for 2 weeks.. well they are both nice rides, so i'm def not complaining.

 

[MrElussive]

I'm loving my G35 Coupe. BMW has more character, though (driver-vehicle connection).

 

[andreyiv]

I saw a G35 coupe today and one thing I really like about it's appearance is, the straight doors, it would be so easy to California Water Blade it, . It takes me twice as long to get the doors dry compared to any other part of the car.

 

[Average Jae]

i really like the way the front looks, but i'm not a big fan of the rear lights, and the super small trunk.. even if it does take in 2 golf bags.. and the no split fold backseats also seems a bad design choice. but i'm nitpickin ain't i?

 

[MrElussive]

It is easy as hell to Water Blade it, exept the hood, because where the lights are, there are two little arches that are weird, but whatever, it's worth it.
Jae, the trunk definitely is tight...I think it's only 7.8 cubic feet. As for the rear seats, you just pull a latch and it folds down...they fold, but they are not split-folding. So it's either the whole thing down or the whole thing up.
And it's not nitpicking...as it was said in Vanilla Sky, "It's the little things that count...there's nothing bigger, is there?"

 

[mikev]

For general crusing BMW recommend driveing at between 2,000 and 3,000Rpm.

 

[Average Jae]

 

[torpedo]

Must be nice to have 6 speed. What's RPM like when you are cruising at 70 mph? mine is over 3K at 5th gear. I only have 5 spd (2002 325i)

 

[Average Jae]

normally i'd say there isn't much difference btw the overdrive gear on the 5 speed or a 6 speed. cept in the case of bimmers.. seems the 5 speed manus don't have overdrive gear ratios, but rather direct gearing; near 1:1 ratio. even with that they get great highway milage.

but in case of other cars w/ 5th gear being overdrive gear, and 6 gear trannys, the overdrive gear ratio is similar. it's just that with 6 gears, engineers can space out the gears for optimal acceleration. or something like that..

i'm around 2.5k or so at 70.. dun remember exactly, but i's about 500 lower..

 

[chsu74]

Must be nice to have 6 speed. What's RPM like when you are cruising at 70 mph? mine is over 3K at 5th gear. I only have 5 spd (2002 325i)

I have a 2001 325Xi and I cruise a little bit over 3K at 5th gear rolling at 70 PMH.