3000 rpm at 65mph?

[96eclipsegsx56]

Is it normal to be at 3000+ RPMs at 65+ MPH in 5th gear?

 

[WES_393]

Anyone saying its "not worth" $225 for the taller 5th is on crack, ESPECIALLY if you drive your DSM a lot, you'll easily make up the initial investment in fuel savings within the first 6 months.

$225 is about 56 gallons of gasoline. How long would it take to SAVE 56 gallons of gas from swapping the gear? Even if you upped your gas mileage from 25mpg to 27mpg, you would have to drive 19,000 miles to get back your initial investment.

I'm not on crack, I know how to use a calculator. Evo 5th gear is not worth it.

 

[Calan]

Evo 5th gear is not worth it.

It is if it drops your cruise RPM point below the drone threshold of your exhaust.

 

[JusMX141]

I wish the cars just had a damn 6-speed...and not a close-ratio 6-speed like the Evo's where their 6th is nearly the same as our 5th- I mean an actual 6th gear that would drop the cruising RPMs down to 2000-2200 on flat ground or for downhills. Yeah you'd shift more, but the fuel savings would be more than worth it.

 

[Calan]

Wouldn't that be sweet?

I'm surprised nobody has come up with something. I'd rank that right up there with the ability (or lack of) to change the front/rear torque split.

 

[boost97gst]

3k at 70mph. 18 in rims

 

[nicks tsi]

A 6th gear would be lovely

 

[Abe'sGST]

Yes, I always wondered why wouldn't they just come up with a 6 speed tranny. But for know all I can do is just wait until I get my evo 5th gear, Ill be happy with that

 

[95TalonOwner]

Put the neon gear set in my NVT-350 trans and went from 3000rpm at 65ish down to 2200rpm at 65mph.

 

[Archer Fabrications]

i wonder if you could rig something up if you just had a custom bell housing...? ive seen people CNC a bell housing to fit the is300 supra 6 speed trans to a 4g63? i dunno where that thread is but its tight as a nuns "()"

 

[cliffkemp]

If you want better mpg, put taller tires on so you will be going faster than you think but, make sure you know about how fast you are going

For those rebuilding their engine, go with higher than stock compression. The higher the better (to an extent) so that off boost power will be decent. I hear that most go with 8.8 to 9.0.

If you are not doing the 2 above, just practice letting off the gas coasting down hill. This turns the injectors off (unless something is wrong) and you will get better mpg this way as well.

Keep in mind that a taller gear will do just so much depending on weight, rolling resistance, and load on the motor due to these. Low airpressure, wider wheels, excessive weight (keep your cars clean) all contribute to lower mpg.

 

[Miakehl]

$225 is about 56 gallons of gasoline. How long would it take to SAVE 56 gallons of gas from swapping the gear? Even if you upped your gas mileage from 25mpg to 27mpg, you would have to drive 19,000 miles to get back your initial investment.

I'm not on crack, I know how to use a calculator. Evo 5th gear is not worth it.

If you're already in the tranny doing work it makes sense. Any increase in mileage is better than no increase.

Some of us that drive the dog crap out of the highway can make use of it. I drive 600 miles a week to and from work on the highway at 75mph. Even though I get between 30-35 mpg at $3.69 a gallon I'll take whatever break I can get.

 

[mattasi]

It is if it drops your cruise RPM point below the drone threshold of your exhaust.

Exactly, the EvoIII 5th gear made my car so much quieter on the highway.

 

[YanDsm]

Our cars are build for high rpm hp and torque, make them rev lower doesn't mean that you'll get a better mileage. It's better to get the engine rev higher with no load instead of lower rpm with steady load. I know that its not a car but it's similar : My sister bike is a 2010 kawasaki ninja 250r, at 60 mph it rev at 8000RPM!!!! and do 75mpg because there is almost no load on the engine!!!!!!

 

[99 E-klips gs]

I sit at 78 @ 3000 rpms

 

[cliffkemp]

Our cars are build for high rpm hp and torque, make them rev lower doesn't mean that you'll get a better mileage. It's better to get the engine rev higher with no load instead of lower rpm with steady load. I know that its not a car but it's similar : My sister bike is a 2010 kawasaki ninja 250r, at 60 mph it rev at 8000RPM!!!! and do 75mpg because there is almost no load on the engine!!!!!!

This is where you are incorrect. Also, comparing a bike with far less weight, less rolling resistance, and way different power band is inaccurate.

The best mpg is only achieved at rpms that reflect the most tq off boost in these cars. This is almost always in the 2k to 3k rpms range on just about any car. Load only has to do with keeping mpg high only if you are going down hill as the injectors will not be on if you are not pushing on the gas. A bike weighs 5x less than our cars is a bad example. It has just 2 wheels and at 8000 rpms, with the powerband they have, that is like 3k in our cars.

You do not want to gear the cars too low but, if you drive in the range in which max tq occurs off boost, that will be the best mpg. I have tested this time and time again in my rx8 and keeping rpms low so that when you do hit the accelerator, fuel delivery is minimal to maintain speed, that is when you get the best mpg. This holds true in any car. My neon is the same way.

The best way to get good mpg is to have little engine braking on downhill runs so that your injectors are off as long as possible (this is where the taller gear helps as it puts less engine braking into effect since it is taller and, therefore, does not slow the car down as much as a shorter gear will do when you let off the accelerator). On the uphill run, hit the accelerator just enough to maintain speed. This is the whole concept of a cruise control to help with mpg. The difference is, we can do it better than a cruise if we really try to.

I would just like to add that a 250cc engine sips gas at just about any rpm. I had a 100cc bike and it would go for days on 3 gallons. My father had a 1980 250 suzuki enduro. Same thing, he drove it days before fill ups cause the engine was so small and did not use much gas in the first place.

Apples to chickens here....

I sit at 78 @ 3000 rpms

very similar to my neon with the .72 5th and 3.55 final. It will cruise at around 80 at 3k. I used to get around 40 mpg with it.

 

[95talongirl]

.. was wishing for a 6-speed not long ago after a long road trip. Had a turbo 2012 Chevy Cruze with a 6-speed auto and was shocked to see it cruise at 2700rpm..... at 80mph! haha! I'm used to the Talon sounding screaming at 3200-3400 or so at 80.

 

[Archer Fabrications]

Im at 70mph at 3000 rpm out of boost cause i lag up to 4500 but 3k is a nice whisteling dump truck sound

 

[jrohner]

Our cars are build for high rpm hp and torque, make them rev lower doesn't mean that you'll get a better mileage. It's better to get the engine rev higher with no load instead of lower rpm with steady load. I know that its not a car but it's similar : My sister bike is a 2010 kawasaki ninja 250r, at 60 mph it rev at 8000RPM!!!! and do 75mpg because there is almost no load on the engine!!!!!!

Our engines are 8 times bigger, vehicle weighs 6 times as much (including driver/rider), and has 7 times the HP STOCK (mine has 15+ times the HP); how is that similar?

I rode a Ninja 250 one day, and just beating the crap out of it full WOT for 1-2 miles straight at a time and still got 52MPG. My car would get single digits for mileage even going the same speed as that bike.

 

[BigKnick]

I have driven my GSX from NC to NY just over 12 hours straight (except for three fuel stops and to piss ocassionally) around 75mph and 3100 or 3200 the whole way I have made this trip three times in thye last year and not had a single problem!

 

[ramsack]

This is just the nature of small 4 cylinder engines. They have pathetic torque. This is why the adage of "there's no replacement for displacement" is perfectly sound logic that can not be beaten.

 

[EverettGSX]

I have 18" and I do 2300ish at 60mph
I have Evo III 5 gear upgrade

 

[daren_p]

I have 18" and I do 2300ish at 60mph
I have Evo III 5 gear upgrade

Think your tach might be out, have you compared its reading to the ecu's reading? (unless you have crazy over sized tires).

Some others in this thread seemed to overestimate the drop in rpms abit from the evoIII 5th gear. I have the evoIII 5th gear, I would ballpark its drop about 300rpm vs the stock gear (possibly up to 400rpms, it been awhile since I've driven the car ).

 

[Tiki2777]

This is just the nature of small 4 cylinder engines. They have pathetic torque. This is why the adage of "there's no replacement for displacement" is perfectly sound logic that can not be beaten.

Yea, lets just bash the 4 cylinder on a DSM forum... DUR
WTF

 

[EverettGSX]

Think your tach might be out, have you compared its reading to the ecu's reading? (unless you have crazy over sized tires).

Some others in this thread seemed to overestimate the drop in rpms abit from the evoIII 5th gear. I have the evoIII 5th gear, I would ballpark its drop about 300rpm vs the stock gear (possibly up to 400rpms, it been awhile since I've driven the car ).

No I haven't, I thought its normal, how do I check tht? In the shop?

 

[Mello]

I have the EVO III 5th in my GST and 65 is at 2325 running P225/40R18's. My GSX does 65 at 2750 running P225/50R16's.