Is 3900 rpms at 70 mph bad? this really worries me when i am goin 70. I dont want to overheat the engine.

is there anything i can do to lower it?

your cool dont worry, they are all like that, i asked the same question six months ago, and the response i recieved was along the lines of the transmision being geared to be "peppy" rather than sluggish , but everyone i knows is like that, @80mpf mine cruises around 4000

brent

Yeah, once you're in 5th gear it's about 50rpm for every 1mph (3k @ 60mph, 5k @ 100mph, etc...)

i can't stand driving slow..
i beat the crap out of the car and never over heated.

i managed to go from la jolla to city of industry in about 1hour and 15 mins.

I would go on a range from 85-110 back and forth depending on traffic and turns.
RPMS STAY HIGH ___.. at first im worried but now i just got used to it..
what can u do?

Is 3900 rpms at 70 mph bad? this really worries me when i am goin 70. I dont want to overheat the engine.

is there anything i can do to lower it?

You won't overheat it at cruise. Now, if you are climbing a steep hill in summer it might more likely.

In order to make the heavier car feel "quick" Toyota put a very high (numerically speaking) final drive ratio on the Scions. The penalty is high cruise RPM and probably reduced longevity. It was a lot cheaper to do this than to replace the transmission gearsets or (gasp) offer a 6-speed.

The solution isn't all that cheap. The Echo final drive might fit and would lower engine RPM by about 25%. A partial solution is to fit larger diameter tires, which would lower engine RPM by about 10% max.

George

I guess this is a manul tranny issue (70@3.9k rpm)? At 70MPH, mine (auto-tranny) is at 3K. Then again, I drive slowly to 70MPH on a flat freeway.

no its not a manual issue...
i have a manual and at 4,000rpm im doing exactly 80mph.....

figure it this way 1mph = 50rpm in 5th gear.... so 4000rpm divided by 50 = 80mph

Is 3900 rpms at 70 mph bad? this really worries me when i am goin 70. I dont want to overheat the engine.

is there anything i can do to lower it?

if your really going 3900rpm at 70mph you might have a problem...clutch slipping maybe...
did you change your tires....if so what size...if u went to a smaller diameter tire this would cause that.....
if you have a automatic tranny....your torque converter could have a problem and is not locking anymore

i have 17's on mine. but they are pretty close to stock size wheels with tires. so i dunno... it worries me, but if there isnt anything i can do, oh well. :?

With stock rubber and wheels, my auto does 3500 @ 80MPH consistently...

Damn kids messing around near my PC. Sorry for the double post

Is 3900 rpms at 70 mph bad? this really worries me when i am goin 70. I dont want to overheat the engine.

is there anything i can do to lower it?
and he said 3900 at 70mph....thats way high for stick or auto....go to your local dealer and ask a tech in service about it....

I spent ALL DAY at texas world speedway between 5 and 6krpms at full throttle and the engine never even got warm.

Its a tiny, modern engine, 4krpms isn't bothering it at all.

for what it's worth. I've had an xA standard for a few weeks. stock 15" tires. 60 mph = 3000 rpm. 70 mph = 3500 rpm.

I can cruise at 80mph at just over 3k rpm.

KiL

for what it's worth. I've had an xA standard for a few weeks. stock 15" tires. 60 mph = 3000 rpm. 70 mph = 3500 rpm.


doesn't matter what wheels/tires you have

an INDICATED 70mph will always be at 3,500rpms

for what it's worth. I've had an xA standard for a few weeks. stock 15" tires. 60 mph = 3000 rpm. 70 mph = 3500 rpm.


doesn't matter what wheels/tires you have

an INDICATED 70mph will always be at 3,500rpms

yes it does matter

if you have an oversize wheel then the rpm will be alot lower
ive had 19s on my benz stock size was 14s and my rpm is wayyy low

The speedometer is based on how many times the wheels turn around.

when you get tires with a different sized diameter, the speedometer will be wrong.

So yes, if you got huge tires, the rpm when you are *actually* going 70mph will be lower.

but the rpm when your speedo *indicates* you are going 70 will be the same.

unless your car uses GPS or an optical sensor under the car to gauge its speed (And it doesnt)


for what it's worth. I've had an xA standard for a few weeks. stock 15" tires. 60 mph = 3000 rpm. 70 mph = 3500 rpm.


doesn't matter what wheels/tires you have

an INDICATED 70mph will always be at 3,500rpms

yes it does matter

if you have an oversize wheel then the rpm will be alot lower
ive had 19s on my benz stock size was 14s and my rpm is wayyy low

I checked it this morning on the way home from work. At 70mph on a flat stretch I was steady @ 3500rpm. I have stock wheels and tires on the box.

Nope, still 3K@70mph as before. How about tire pressure? Recommended on stock steelies/tire is 29/30psi as per manual. I'll check my cold air pressure early tomorrow morning.

Nope, still 3K@70mph as before. How about tire pressure? Recommended on stock steelies/tire is 29/30psi as per manual. I'll check my cold air pressure early tomorrow morning.


doesn't matter what your tire pressure is

doesnt matter if you have lego wheels or monster truck wheels.

when the speedo says 70mph the tach is gonna say 3500 if you have the 5speed.

doesn't matter what your tire pressure is

doesnt matter if you have lego wheels or monster truck wheels.

when the speedo says 70mph the tach is gonna say 3500 if you have the 5speed.

*nod* Whether or not you're really going 70mph is another story...

[quote=OC Scion]

The solution isn't all that cheap. The Echo final drive might fit and would lower engine RPM by about 25%. A partial solution is to fit larger diameter tires, which would lower engine RPM by about 10% max.

George

I am really interested in this Echo final drive. Do you think it would throw the ECU out of whack? :?:

Also, How "not cheap" are we talking here? 1000$? More?

Thanks 8)

To get my stock automatic to 4000RPMs, I"ve gotta be pushing a solid 90+MPH

XB Automatic... im around 3200-3400 rpms at 80 mph

xb auto, 3000 RPM @ 70.

The solution isn't all that cheap. The Echo final drive might fit and would lower engine RPM by about 25%. A partial solution is to fit larger diameter tires, which would lower engine RPM by about 10% max.

George

The echo final drive might fit, but really you would need to talk to a tranny specialist to remove the guts of the tranny and replace the gears/final drive. Having less teeth on the gears will cause the RPMs to come down and thus making our vehicles last longer, I have been researching this for a while, since my brother shop is Precision Transmissions. After the main warranty goes out I am removing the tranny and replacing all the gears and final drive.

Find out more about trannys at www.precisiontranmissions.com just click on the FAQ area.

Anyone able to inform me as to how the xB runs at near 100? Due to my large 15 size feet they weigh more you see,...so the pedal is pushed farther down :roll: . Actually I can't stand anything less than 90 on the freeway. Around towning is always 50-60 unless school zone...I'm not a complete pyscho. Tee hee.

Anyone able to inform me as to how the xB runs at near 100? Due to my large 15 size feet they weigh more you see,...so the pedal is pushed farther down :roll: . Actually I can't stand anything less than 90 on the freeway. Around towning is always 50-60 unless school zone...I'm not a complete pyscho. Tee hee.

ive cruised at around 90 for extend periods on the higway without ill effect

gas mileage isnt anywhere near the rated 36mpg or whatever tho when you get above 70mph =)


hell I ran all day at texas world speedyway constantly near redline and the engine didn't complain one bit.

I guess this is a manul tranny issue (70@3.9k rpm)? At 70MPH, mine (auto-tranny) is at 3K. Then again, I drive slowly to 70MPH on a flat freeway.

no, it is not normal.....it should be around 4k rpm @ 80mph, not 70mph...

at least that is what mine does.....and i have 5 speed...

the auto is supposed to have higher RPMs then the 5 speed. The auto is a 4 speed and the manual is 5. I know because when I make a manifold back system for any scion, I have to ask if it is an auto or stick. The auto is louder on the freeway then the manual. I have done testing and heard the complaints! :lol:

does anyone know what gear ratio is in the axle? i thought i read somewhere that it had 4.11's so the it could make better use of the 108hp. if this is so then of course it turns 4k at 80, that what my 5speed does too. its the price you pay for low gears and a little engine.

Maybe I;m nuts but my xb auto tops at 3200rpm's at 80mph with 15's.