New Cobalt MPG will the HHR be next?
#11
The therory is that if you drive economically with the manual transmission and shift at low RPM's your mileage will always be better then an automatic.
#12
I think the addition of a 6th gear would help the most, something that would run the engine ~2000 RPMs at 70 MPH
Sadly 5th gear (on mine) seems optimized for 45-50 MPH. Resetting the Economy counter before cruising at those speeds for ~5 miles can net me 40-45 MPG.
With another gear one could drive across the country at 70 MPH and still get 40 MPG I bet
Sadly 5th gear (on mine) seems optimized for 45-50 MPH. Resetting the Economy counter before cruising at those speeds for ~5 miles can net me 40-45 MPG.
With another gear one could drive across the country at 70 MPH and still get 40 MPG I bet
#13
Things like electronic control and lockup converters have much improved the efficiency of auto trans in recent years. Still, you have hydraulics in place that rely on pressure provided by a pump (read: HP loss). Driven sensibly, a manual will still get better MPG than an auto, all else being equal.
Given the original information, a 3 MPG gain is easily attainable. Chevy has likely spec'd a tire with less rolling resistance and has tweaked the spark tables for better economy. They may also have gone slightly lean on the calibration, although that's difficult and still be able to meet emission standards when the AFR deviates from stoic.
I tuned my HHR and easily exceed the published (old or new) specs by more than 3 MPG, but I also hate it when people start trying to compare mileage, since there are so many variables that make comparisons moot.
Given the original information, a 3 MPG gain is easily attainable. Chevy has likely spec'd a tire with less rolling resistance and has tweaked the spark tables for better economy. They may also have gone slightly lean on the calibration, although that's difficult and still be able to meet emission standards when the AFR deviates from stoic.
I tuned my HHR and easily exceed the published (old or new) specs by more than 3 MPG, but I also hate it when people start trying to compare mileage, since there are so many variables that make comparisons moot.
#15
If high mpg numbers are the goal, GM should look to clean diesel. Admittedly, diesel prices right now are a little crazy, but diesel returns more efficiency than gasoline. The wife's 2005 Beetle TDI (5-speed manual) got 49.6 mpg on her Nashville trip last weekend, and that was pacing with traffic around 80mph cruise ctrl active, and through hilly western KY & TN. She said she started out trying to drive 75 but was practically getting ran over, so she upped it to keep better pace w/ everyone else. Gasoline version of the Beetle only gets slightly better than half that.
In keeping with the topic of this thread, I will add that her Beetle uses full synthetic oil (has to for warranty, use VW spec 505.01 compliant oil which is full synth diesel oil), and the OE tires are 205/55HR16 Michelin "Energy" MX which I suspect to be a low rolling resistance energy saver tire from Michelin, and I bet the Cobalt XFe OE tire may be the same type.
In keeping with the topic of this thread, I will add that her Beetle uses full synthetic oil (has to for warranty, use VW spec 505.01 compliant oil which is full synth diesel oil), and the OE tires are 205/55HR16 Michelin "Energy" MX which I suspect to be a low rolling resistance energy saver tire from Michelin, and I bet the Cobalt XFe OE tire may be the same type.
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amberelyse
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07-22-2006 05:57 PM