Any reason why I was getting 10.7mpg?

[Beanmachine7000]

At 55 in OD with 3.73's you should be about 1800rpm... If you did lose OD you will be running at 2400rpm... I don't think that's your problem though... running at 2400rpm instead of 1800rpm at 55 will increase your gas mileage, not decrease...

 

[baxtej44]

At 55 in OD with 3.73's you should be about 1800rpm... If you did lose OD you will be running at 2400rpm... I don't think that's your problem though... running at 2400rpm instead of 1800rpm at 55 will increase your gas mileage, not decrease...

any spec's for a lower speed?


i can hit 40 on my way to school.. but 55 is gonna be pushin it

 

[Beanmachine7000]

1300rpm for 40... Just put it in D and drive up to 40, then move the shifter lever to OD... You should hear it drop into OD and can watch the tach drop down... Like I said though, you would only get better gas mileage by running it in D...

Oh, I assumed you have 3.73 gear ratio, so if my numbers are a few hundred off it's nothing to be worried about, it just means you have 3.55's instead...

 

[Mechanickid]

I had an 86 ranger and at the time I had it (I was 16) I didn't realize it but the torque converter was slipping reallllllly bad and it ran 3300 rpm at 70 mph in OD.

 

[baxtej44]

1300rpm for 40... Just put it in D and drive up to 40, then move the shifter lever to OD... You should hear it drop into OD and can watch the tach drop down... Like I said though, you would only get better gas mileage by running it in D...

Oh, I assumed you have 3.73 gear ratio, so if my numbers are a few hundred off it's nothing to be worried about, it just means you have 3.55's instead...

Okay, I will give you the RPM in "D" at 40mph, and will give you the RPM in "O" at 40mph... I actually heard you get better in "O"... which one is better mpg??!??! O or D... grr..

I had an 86 ranger and at the time I had it (I was 16) I didn't realize it but the torque converter was slipping reallllllly bad and it ran 3300 rpm at 70 mph in OD.

idk what that means haha... hopefully that's just you, because it doesn't sound cheap, and obviously not good

 

[Beanmachine7000]

Drive is 1:1 (every time your engine turns once, your driveshaft turns once) Overdrive is 0.75:1 (every time your engine turns 0.75 turns your driveshaft turns once)

You will get better gas mileage when you can keep your engine in it peak torque range (2600-2800 for the 2.9) Therefore at 55mph your engine will be operating more efficiently in D than OD... Though at 70mph OD would give you better fuel economy...

I still think this is a CTS problem... You wouldn't get this bad mileage if you didn't have OD...

 

[baxtej44]

Drive is 1:1 (every time your engine turns once, your driveshaft turns once) Overdrive is 0.75:1 (every time your engine turns 0.75 turns your driveshaft turns once)

You will get better gas mileage when you can keep your engine in it peak torque range (2600-2800 for the 2.9) Therefore at 55mph your engine will be operating more efficiently in D than OD... Though at 70mph OD would give you better fuel economy...

I still think this is a CTS problem... You wouldn't get this bad mileage if you didn't have OD...

Okay, well I have someone who is supposed to be e-mailing me some scanned pages out of a manual to mix the CTS...

So just so i know.... for slower city speeds, 1-45 or 50 I should use drive? but if I am on the interstate or highway, 55-75 overdrive is better?




=======edit=======

oops, that "someone" is you, beanmachine... haha.
not rushing you.. just sayin.

I'm in no rush because I can't do any work probably until this upcoming weekend anyway.

 

[Beanmachine7000]

I would just leave it in OD unless you plan on driving at 55mph for a long time... Switching back and forth won't be worth it for a short jaunt... Honestly, I haven't even gotten back to my house yet, haha... I'll get that stuff to ya tomorrow afternoon...

 

[baxtej44]

I would just leave it in OD unless you plan on driving at 55mph for a long time... Switching back and forth won't be worth it for a short jaunt... Honestly, I haven't even gotten back to my house yet, haha... I'll get that stuff to ya tomorrow afternoon...

okay, and no problem... this site is so great for help.

I hope to be half as helpful as most of you on here, someday lol.

 

[Beanmachine7000]

You will... I'm not as knowledgeable as half the people here... I just turned 21, but I've been working with my dad on cars ever since I can remember... The number one thing I can say to motivate you is to just get out there and do it... I bought a Camaro when I turned 18 and hopping up that car has been the biggest learning experience in my life... First time taking apart an engine, and putting one back together... First time doing exhaust, setting up a rear end, first cam swap... I never let it stop me though... I just started taking it apart, figuring out what did what, and how it worked, and making sure it went back to together right... If you can figure out HOW something works by looking at the pieces, you will learn SOOO much more than just reading... I would suggest reading before taking things apart though I'll get ya that stuff tomorrow afternoon... Good luck...

 

[Shran]

lol well how would i know if something is wrong?

and ya... sounds like you're speaking german to me.. anyway, any links out there that can explain that.. with pictures and such?

Your Chilton's or Haynes manual, if you have one, will tell you how to test it and replace it. You need a multimeter to test for resistance, I believe.

Mine with 3.73 gears and 215/70 tires hits about 2600RPM at 70MPH in OD. FYI.

 

[baxtej44]

Your Chilton's or Haynes manual, if you have one, will tell you how to test it and replace it. You need a multimeter to test for resistance, I believe.

Mine with 3.73 gears and 215/70 tires hits about 2600RPM at 70MPH in OD. FYI.

hm, i don't have one of those.. but i'll see if i can convince my physics teacher to let me borrow one, and if i don't bring it back... he can fail me haha.

 

[feellnfroggy]

No it's not, there is maybe a 1MPG loss. Ranger's fuel economy didn't drop 5MPG when they switched to live axle

I spent 15 months in Iraq driving Humvees with full time 4x4 (as far as the front dfrive train is concerned.

Also my expedition is fulltime locked front drivetrain.

But if you think about it with a little common sense. Which is harder to get rolling? a wheel? or a wheel with a whole driveline attached to it? If the a/c drops us 4-5 mpg, (maybe 2-3 ont he 4 cyl) and thats power robbed at the motor then what the hell is the driveline gonna rob us?

When he has his hubs locked his motor is turning the wheel, cvtype axle, (we always called them halfshafts,) the gears in the front diff, and the front driveshaft. When I say its pushing it I dont mean power to those front wheels because its obviously not in 4x4, its just locked. But the wheels provide resistance, as opposed to locked hubs the whole front driveline provides resistance.

I was guestimating mileage improvement numbers, those arent factual. they were my opinion of what his increase would be based on my epxeriences. That is the kind of info we provide here right? I could be wrong, but I doubt I will be far off.

 

[baxtej44]

approximate rpm at 40mph

in drive:
2100

in o:
1500


could be off by a couple hundred.. but won't be too far off if i remember correct

 

[88gt]

your battery cables might be corroded inside the rubber coating. that killed my mpg from 20 to 13 empty on a 2wd truck. i would strongly suggest changing those if you never did or dont recall the last time you did.