High RPM's ??
March-28th-2003, 06:41 PM
#1
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Join Date: Mar 2003
Location: Boston/Providence
Posts: 59
High RPM's ??
Hi guys,
I just got my protege. Its a 2002 LX lefty. I love the car, but i've got a question. Has anyone noticed that driving on the highway how high the RPM"s are ? I dont know if its normal for a pro, because this is the first i've driven. With other cars I've driven, some with smaller engines, going 80 or so the RPMS are at arond 3 grand, plus or minus a few hundred. With the pro, i'm up to about 4 grand. even 75 mph is about 3500. THis is in 5th gear, of course. Is it just the gear ratio ? any ideas ?
I just got my protege. Its a 2002 LX lefty. I love the car, but i've got a question. Has anyone noticed that driving on the highway how high the RPM"s are ? I dont know if its normal for a pro, because this is the first i've driven. With other cars I've driven, some with smaller engines, going 80 or so the RPMS are at arond 3 grand, plus or minus a few hundred. With the pro, i'm up to about 4 grand. even 75 mph is about 3500. THis is in 5th gear, of course. Is it just the gear ratio ? any ideas ?
March-29th-2003, 03:50 PM
#6
Cripple Fight!!!!
Join Date: Nov 2001
Location: Northern VA
Posts: 1,944
Re: High RPM's ??
Originally posted by sunil6784
Hi guys,
I just got my protege. Its a 2002 LX lefty. I love the car, but i've got a question. Has anyone noticed that driving on the highway how high the RPM"s are ? I dont know if its normal for a pro, because this is the first i've driven. With other cars I've driven, some with smaller engines, going 80 or so the RPMS are at arond 3 grand, plus or minus a few hundred. With the pro, i'm up to about 4 grand. even 75 mph is about 3500. THis is in 5th gear, of course. Is it just the gear ratio ? any ideas ?
Hi guys,
I just got my protege. Its a 2002 LX lefty. I love the car, but i've got a question. Has anyone noticed that driving on the highway how high the RPM"s are ? I dont know if its normal for a pro, because this is the first i've driven. With other cars I've driven, some with smaller engines, going 80 or so the RPMS are at arond 3 grand, plus or minus a few hundred. With the pro, i'm up to about 4 grand. even 75 mph is about 3500. THis is in 5th gear, of course. Is it just the gear ratio ? any ideas ?
most other company's compact cars are geared for fuel economy, while Mazda gear it so it's more fun to drive
March-29th-2003, 11:23 PM
#7
Protege Newbie
Join Date: Oct 2002
Location: Renton, WA
Posts: 34
Re: Re: High RPM's ??
Originally posted by ZoomZoomH
yup that's perfectly normal, Proteges have lower gearings compared to its competitions
most other company's compact cars are geared for fuel economy, while Mazda gear it so it's more fun to drive
yup that's perfectly normal, Proteges have lower gearings compared to its competitions
most other company's compact cars are geared for fuel economy, while Mazda gear it so it's more fun to drive
Mazda should have geared 5th (and 4th on the auto tranny) to have 70mph cruising available at just under 3000rpm...and maybe around 2800rpm for the auto tranny. 1st through 4th could be short but 5th should be taller than it is...if you need to pass on the highway downshift. They probably could of even hit closer to 32-33mpg highway gas mileage.
March-30th-2003, 12:48 AM
#9
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Join Date: Mar 2002
Location: State College, PA
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Originally posted by PinkMX-3
Realise that gas consumption is not a direct function of rpm, but rather of Brake Specific Fuel Consumption, which could be lower at 3500RPM than 3000RPM.
Realise that gas consumption is not a direct function of rpm, but rather of Brake Specific Fuel Consumption, which could be lower at 3500RPM than 3000RPM.
And the reason for a shorter fifth is better passing power on the highway + not having to down shift every time the road starts to creep uphill. If you had to downshift every time you wanted to pass a truck on the interstate, this thread would be dedicated to "why do Protege's have such a tall 5th gear?"
March-30th-2003, 12:51 AM
#10
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Join Date: Oct 2002
Location: Renton, WA
Posts: 34
If the throttle position is the same at 3000rpm and 3500rpm I can guarantee you that the BSFC will be lower at 3000rpm. Only when it takes a greater throttle position at the lower rpm will the BSFC be higher than at a higher rpm...
March-30th-2003, 12:57 AM
#11
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Join Date: Oct 2002
Location: Renton, WA
Posts: 34
Originally posted by Installshield
Exactly....
And the reason for a shorter fifth is better passing power on the highway + not having to down shift every time the road starts to creep uphill. If you had to downshift every time you wanted to pass a truck on the interstate, this thread would be dedicated to "why do Protege's have such a tall 5th gear?"
Exactly....
And the reason for a shorter fifth is better passing power on the highway + not having to down shift every time the road starts to creep uphill. If you had to downshift every time you wanted to pass a truck on the interstate, this thread would be dedicated to "why do Protege's have such a tall 5th gear?"
Lets see my Mirage with a tiny little 1.8L engine runs at about 2800rpm in 5th gear when cruising at 70mph. I NEVER have to downshift on any hills...I don't even need to downshift if I am passing someone unless I am trying to pass them extremely fast. My engine is only 113hp stock with a peak torque that is at 4500rpm so you would think that my BSFC would be much higher at low rpms than the protege's due to the lower peak torque (signalling volumetric efficiency is reached at a lower rpm in the protege).
Last edited by dude ina mirage; March-30th-2003 at 01:00 AM.
March-30th-2003, 11:02 AM
#12
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Join Date: Apr 2002
Location: Pittsburgh, PA
Posts: 77
Better fuel mileage
You want better mileage, pump up the air pressure in your tires from the recommended 32 psi to about 35-36 psi.
I actually like the cars reactions better at this air pressure. My last trip from Pittsburgh to Altoona, then over to State College and back to the Burgh netted me about 32.4 mpg, and this is a combination of four lane, two lane and lots of gradient and speed changes. This on an '02 ES manual tranny with only one person in the car. Speeds ranged from stop and go to about 85 mph.
I actually like the cars reactions better at this air pressure. My last trip from Pittsburgh to Altoona, then over to State College and back to the Burgh netted me about 32.4 mpg, and this is a combination of four lane, two lane and lots of gradient and speed changes. This on an '02 ES manual tranny with only one person in the car. Speeds ranged from stop and go to about 85 mph.
March-30th-2003, 11:12 PM
#13
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Join Date: Mar 2002
Location: State College, PA
Posts: 1,069
Originally posted by dude ina mirage
My wife's Protege is auto and it automatically downshifts out of overdrive every time I am on a hill...If you REALLY wanted to pass someone you don't do it in 5th gear. It is ordinarily the "cruising" gear not the passing gear.
Lets see my Mirage with a tiny little 1.8L engine runs at about 2800rpm in 5th gear when cruising at 70mph. I NEVER have to downshift on any hills...I don't even need to downshift if I am passing someone unless I am trying to pass them extremely fast. My engine is only 113hp stock with a peak torque that is at 4500rpm so you would think that my BSFC would be much higher at low rpms than the protege's due to the lower peak torque (signalling volumetric efficiency is reached at a lower rpm in the protege).
My wife's Protege is auto and it automatically downshifts out of overdrive every time I am on a hill...If you REALLY wanted to pass someone you don't do it in 5th gear. It is ordinarily the "cruising" gear not the passing gear.
Lets see my Mirage with a tiny little 1.8L engine runs at about 2800rpm in 5th gear when cruising at 70mph. I NEVER have to downshift on any hills...I don't even need to downshift if I am passing someone unless I am trying to pass them extremely fast. My engine is only 113hp stock with a peak torque that is at 4500rpm so you would think that my BSFC would be much higher at low rpms than the protege's due to the lower peak torque (signalling volumetric efficiency is reached at a lower rpm in the protege).
I have no trouble accelerating on most hills, or picking up 15mph when passing on a highway in 5th gear. Top gear acceleration in a Protege5 is the best in it's class according to Car and Driver.
How much does your Mirage weigh?
March-31st-2003, 12:25 AM
#14
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Join Date: Oct 2002
Location: Renton, WA
Posts: 34
Originally posted by Installshield
Protege's use grade logic and automatically deactivate O/D when traveling up hill. Prevents it from hunting...
I have no trouble accelerating on most hills, or picking up 15mph when passing on a highway in 5th gear. Top gear acceleration in a Protege5 is the best in it's class according to Car and Driver.
How much does your Mirage weigh?
Protege's use grade logic and automatically deactivate O/D when traveling up hill. Prevents it from hunting...
I have no trouble accelerating on most hills, or picking up 15mph when passing on a highway in 5th gear. Top gear acceleration in a Protege5 is the best in it's class according to Car and Driver.
How much does your Mirage weigh?
Stock the mirage weighed 2400lbs actual weight (fully loaded) currently my race weight is 2180lbs and everyday weight is around 2250lbs or so. [this brings up another complaint...wish the protege were 100lbs lighter but the wife probably enjoys the quietness afforded the protege by the extra weight]
March-31st-2003, 12:55 AM
#15
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Originally posted by dude ina mirage
It should be best in it's class with the gearing it has (and the fact that this isn't a tiny ultra high rpm tuned engine compared to others in its class). My remark on the auto tranny was actually geared towards the remark you made about not HAVING to downshift...but in her protege we have no choice but to downshift.
Stock the mirage weighed 2400lbs actual weight (fully loaded) currently my race weight is 2180lbs and everyday weight is around 2250lbs or so. [this brings up another complaint...wish the protege were 100lbs lighter but the wife probably enjoys the quietness afforded the protege by the extra weight]
It should be best in it's class with the gearing it has (and the fact that this isn't a tiny ultra high rpm tuned engine compared to others in its class). My remark on the auto tranny was actually geared towards the remark you made about not HAVING to downshift...but in her protege we have no choice but to downshift.
Stock the mirage weighed 2400lbs actual weight (fully loaded) currently my race weight is 2180lbs and everyday weight is around 2250lbs or so. [this brings up another complaint...wish the protege were 100lbs lighter but the wife probably enjoys the quietness afforded the protege by the extra weight]
I agree with you that the auto could have a taller top gear, becuase regardless of the gearing it will downshift if you coax the throttle enough...
your Mirage is much lighter than a fully loaded protege...That is why it gets away with a taller top gear...A 3k+ lb loaded protege would not go anywhere in top gear if it was that long despite having more power. 2800 rpm cruising revs is way too far away from the meat of the power band with that weight to accomplish anything but wet spark plugs...