Help!!! RPM's at 65 M.P.H. ???
03-16-2014, 03:17 PM
#1
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Thread Starter
Join Date: 12-20-2009
Location: Redlands, CA
Posts: 49
Help!!! RPM's at 65 M.P.H. ???
I need a little help. I have searched the forums but I haven't found anything related.
I own a 2006 HHR LT 2.4 / Automatic.
I recently had tires installed on the car. I wasn't present when the tires were installed because my wife took the car in when she was at work. She sent me a text asking what tire size was. So I text back 215/50R/17 (which by the way was the tire size that was on the car when she brought it in and the factory also put a sticker on the door jam). I get home that night and notice the new tires look really large. I notice they installed 215/55R/17's. After questioning the tire shop and telling them they installed the wrong size they tell me "that's the size your wife told us to install". I checked what I sent her earlier and that is what I sent her on the text. Not sure why I sent her that but it wouldn't be the first time I "fat fingered" a text. Okay. My bad, whatever. I still think they should have questioned it.
My wife is driving the car for a week or so and she tells me that her car noisy on the freeway and the mileage is bad. I drove it a few days later and noticed the RPM's on the freeway at 65 MPH is 3,400 to 3,500 RPM???? I don't remember it running that high. I don't drive it regularly so I can't remember what it should be running like. It feels like it's not shifting in to 4th gear or the overdrive is not engaged. There is no overdrive shut off button like on my F-150 or Taurus company car. I do count the shifts and feel it shift in to 4th. I thought maybe the taller tires are not allowing the car to shift in to 4th but the car does get in there. There car otherwise is running fine. All new fluids were done at 100k. New plugs and the overhead was done too. Prior to changing the tires the car ran fantastic and mileage was averaging 23 MPG with mostly city driving. The car still runs fine but the RPM thing has me baffled.
I can't pull any codes. Kept my Actron scanner on it while driving and nothing comes up. Also had one of the guys at work hook up his unit that he got on the Snap-On truck and it didn't pick up anything.
Anybody got any ideas?
I own a 2006 HHR LT 2.4 / Automatic.
I recently had tires installed on the car. I wasn't present when the tires were installed because my wife took the car in when she was at work. She sent me a text asking what tire size was. So I text back 215/50R/17 (which by the way was the tire size that was on the car when she brought it in and the factory also put a sticker on the door jam). I get home that night and notice the new tires look really large. I notice they installed 215/55R/17's. After questioning the tire shop and telling them they installed the wrong size they tell me "that's the size your wife told us to install". I checked what I sent her earlier and that is what I sent her on the text. Not sure why I sent her that but it wouldn't be the first time I "fat fingered" a text. Okay. My bad, whatever. I still think they should have questioned it.
My wife is driving the car for a week or so and she tells me that her car noisy on the freeway and the mileage is bad. I drove it a few days later and noticed the RPM's on the freeway at 65 MPH is 3,400 to 3,500 RPM???? I don't remember it running that high. I don't drive it regularly so I can't remember what it should be running like. It feels like it's not shifting in to 4th gear or the overdrive is not engaged. There is no overdrive shut off button like on my F-150 or Taurus company car. I do count the shifts and feel it shift in to 4th. I thought maybe the taller tires are not allowing the car to shift in to 4th but the car does get in there. There car otherwise is running fine. All new fluids were done at 100k. New plugs and the overhead was done too. Prior to changing the tires the car ran fantastic and mileage was averaging 23 MPG with mostly city driving. The car still runs fine but the RPM thing has me baffled.
I can't pull any codes. Kept my Actron scanner on it while driving and nothing comes up. Also had one of the guys at work hook up his unit that he got on the Snap-On truck and it didn't pick up anything.
Anybody got any ideas?
03-16-2014, 04:23 PM
#3
Platinum Member
Join Date: 12-06-2009
Location: Alabama
Posts: 11,112
You might want to take a look and see if the front tires are rubbing on the lower strut spring perch.
That size, 215/55/17, shows around 26.3 in. height which is about the tallest tire you can fit on a HHR.
Transmission? Not sure, but sounds like it's not locking up the torque convertor. The difference in tire size is too small to cause that. I would be looking for something else related to the trans.
That size, 215/55/17, shows around 26.3 in. height which is about the tallest tire you can fit on a HHR.
Transmission? Not sure, but sounds like it's not locking up the torque convertor. The difference in tire size is too small to cause that. I would be looking for something else related to the trans.
03-16-2014, 05:38 PM
#5
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Join Date: 01-23-2009
Location: Fredericksburg,VA
Posts: 24,745
65 MPH should be around 2500 RPM. You are sure the selector is in "D"?
The difference in the tires would not make that difference.
To add to your confusion the tire size for the "standard" LT (not 2LT, that you have) is 215-55X16.
The difference in the tires would not make that difference.
To add to your confusion the tire size for the "standard" LT (not 2LT, that you have) is 215-55X16.
03-16-2014, 06:06 PM
#6
Member
Thread Starter
Join Date: 12-20-2009
Location: Redlands, CA
Posts: 49
True. That size is on the door jam too. My 2LT came with 215/50R/17 Firestones from the factory. I definitely texted the wrong size to my wife so they did what they were told but I still think they should have questioned her and my typo would have been caught.
03-16-2014, 09:46 PM
#8
Moderator
Join Date: 01-23-2009
Location: Fredericksburg,VA
Posts: 24,745
I have to fight with the guys around here to get 215-60X16 tires instead of 215-55X16 which is on the placard.
Oh, BTW your speedo will be showing a slightly higher speed than actual. Calibrate the leadfoot with a GPS.
Oh, BTW your speedo will be showing a slightly higher speed than actual. Calibrate the leadfoot with a GPS.
03-16-2014, 11:28 PM
#10
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Join Date: 06-30-2010
Location: Kannapolis NC
Posts: 25,739
Most GPS units like Garmin and Tom Tom will display your ground speed somewhere on the screen, so compare the GPS ground speed with that indicated on the speedometer to get the error/correction factor.
Even with the correct tire size, speedometers can be off from 5% to the maximum allowable 10%(Federal Law), due to manufacturing variances and tire wear.
Even with the correct tire size, speedometers can be off from 5% to the maximum allowable 10%(Federal Law), due to manufacturing variances and tire wear.