01-14-2011, 06:03 PM | #1 |
Drives: victory red 2010 camaro 2ss/rs Join Date: Mar 2010
Location: bismarck, nd
Posts: 125
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2008 cobalt question
Bought an used 2008 cobalt sport with a 4 speed automatic, driving 75mph on the interstate the car is turning 2800rpms. Service departments I have talked to will give me figures ranging as low as 1900 to as high as 2600. So today I bring it to the dealership and of course the technician says nothing is wrong, could not find any codes. If this true, and the car is running right, this would be the highest any automatic, that I have owned, has turned since a 94 suburu with a 3 speed. and 200rpms higher than any 4 speed I have ever owned.
Just wondering if anyone has had any experience with this car, or similar car, that can confirm this car is running properly or not. |
01-14-2011, 06:35 PM | #2 |
Drives: 2010 1LT SIM A6, 2005 GTO TR A4 Join Date: Jul 2009
Location: Buffalo, NY
Posts: 342
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My old Sunfire ran around 3k when at 70mph so that seems about right.
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01-14-2011, 06:53 PM | #3 |
Drives: 2018 Camaro 2SS Join Date: Aug 2010
Location: Lake Stevens
Posts: 1,005
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maybe the gears were changed out?
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01-14-2011, 07:36 PM | #4 |
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Sounds about right.
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01-14-2011, 09:07 PM | #5 |
I used to be Dragoneye...
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In line with what my 2008 LS is doing. I rarely go above 65 because of it...exponential fuel-economy reductions hurt....
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01-14-2011, 11:04 PM | #6 |
Drives: victory red 2010 camaro 2ss/rs Join Date: Mar 2010
Location: bismarck, nd
Posts: 125
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Just seems strange that over the last 20 years gm has been gearing their overdrive lower, but this one car line they decided to go with nearly 3000 rpm. I have a 2008 impala that runs at 1900 at 75, even my old 96 cavalier with a 4 speed was around 2600.
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01-14-2011, 11:08 PM | #7 |
I used to be Dragoneye...
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It all depends on the engine output/weight of the vehicle, etc...The Camaro is hardly above idle at 55, and not much more than 1600 at 75, I think. But then, it also has a 6-speed with a deep overdrive in 6th...
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01-15-2011, 12:01 AM | #8 |
Moderator.ca
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a little under 3000 rpm for a GM 4banger with a 4 speed hydramatic sounds about right
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__________________ Originally Posted by FbodFather My sister's dentist's brother's cousin's housekeeper's dog-breeder's nephew sells coffee filters to the company that provides coffee to General Motors...... ........and HE WOULD KNOW!!!!__________________ Camaro Fest sub-forum |
01-15-2011, 12:05 AM | #9 |
Moderator.ca
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It should be the exact same as your Cavalier. Same transmission ratios, same overdrive. Only difference would be the OD of the wheels & tires.
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__________________ Originally Posted by FbodFather My sister's dentist's brother's cousin's housekeeper's dog-breeder's nephew sells coffee filters to the company that provides coffee to General Motors...... ........and HE WOULD KNOW!!!!__________________ Camaro Fest sub-forum |
01-15-2011, 08:03 AM | #10 |
Hail to the King baby!
Drives: '19 XT4 2.0T & '22 VW Atlas 2.0T Join Date: Dec 2008
Location: Illinois
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Try this. The inputs are readily available if not in the owers manual.
http://www.csgnetwork.com/multirpmcalc.html
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"Speed, it seems to me, provides the one genuinely modern pleasure." - Aldous Huxley
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01-15-2011, 09:28 PM | #11 |
Drives: 2008 Chevrolet Cobalt Join Date: Jul 2008
Location: Minneapolis
Posts: 112
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Yeah, that sounds right. My 2008 Cobalt Sport does the same about the same at that speed.
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01-15-2011, 10:07 PM | #12 |
Drives: victory red 2010 camaro 2ss/rs Join Date: Mar 2010
Location: bismarck, nd
Posts: 125
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Good to know, buying the car used I had some jitters, so anything slightly different had me concerned at first, but everything seems fine. Also didn't realize until a couple days ago it was suppose to take 91 octane, I was using 89 and that was most likely contributing to the lower than advertised gas mileage.
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01-15-2011, 11:04 PM | #13 | |
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Quote:
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01-15-2011, 11:24 PM | #14 |
Drives: victory red 2010 camaro 2ss/rs Join Date: Mar 2010
Location: bismarck, nd
Posts: 125
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yep, it is buried in the manual. Also wikipedia lists the compression ratio as 10.4:1. But the car doesn't seem as finicky as the camaro.
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