Picked up a Cobalt XFE tonight.

[thornburg]

Originally Posted by Fr3AkAzOiD

50 mpg would be nice but I doubt I'm going to EOC with a new car, just P&G and pump up tires to just under max so I'm still thinking 45+ but 50 may be a stretch.

Paid $12,8XX for the car + taxes and tags. Just got the base model with about $250 in options. Was about $1K under what the Chevrolet website lists as the MSRP.

That looks like more than $1k below MSRP to me. Maybe it's $1k below invoice?

[Beelzebubba]

Originally Posted by Fr3AkAzOiD

Through a business connection with my wife was able to get a great deal on a Chevy Cobalt XFE and just couldn't let it pass.

My Chrystler LHS is still running and I think I got fixed what was causing it to die just as it warmed up as it hasn't done it in 2 or 3 days now but I'm not sure exactly what to do with it.

I could donate it and get a decent tax write off, selling it would get me $500 tops. Was even thinking of giving it to a golf driving range to be one of the cars they just set out there and hit balls at.

I was thinking of doing some experiments with it on hypermiling since it's damn near worthless anyways but wouldn't be able to do that for a good 6 months till my house is finished being built (they havn't even started yet) and I have a garage to work in and place to store things.

Anyways....on to the good news. Tire pressure at stock 35psi (tire sensors), 75 miles driving (80/20 highway/city), light P&G but no EOC, have averaged 42.5 mpg so far.

Figure once I break the car in and get the tire pressure up a bit I'll be able to turn in 45 mpg tanks or better.

GM's XFE models are very interesting. Hopefully, an automotive website or publication will soon have a test drive report available. Since all manual-transmission Cobalt and Pontiac G5 models with the 2.2L are now designated XFE, I'd love to see how they stack up to a similar '07 model. The '07 models were rated at (city/highwyay) 25/34mpg, '08 XFE is 25/36mpg and the '09 will be 25/37mpg.

The XFE represented 9% of June 2008 sales and the Cobalt overall is experiencing huge increases YTD vs. 2007 YTD. Just a few months ago, GM intended to drop the manual transmission on all Cobalt modes except the sportiest "SS" trim level. They've now reversed that decision and even added a third production shift at the Ohio plant where the Cobalt/G5 is made. They have also indicated that they're working on expanding the XFE option to other models.

I'm wondering if they intend to modify the automatic transmission to expand the XFE availability beyond just manual tranmission cars?

[thornburg]

Originally Posted by Beelzebubba

I'm wondering if they intend to modify the automatic transmission to expand the XFE availability beyond just manual tranmission cars?

Throw in a good CVT and I'd think about it.

BTW, does anyone else wonder if the Cobalt XFE could maybe get better milage if it had a few less than 148hp? I'm sure that it would be perfect drivable with 110hp. If you received a half-proportional gain in MPG by changing the displacement and/or tuning of the engine, that would be 41-42MPG highway.

[Fr3AkAzOiD]

The XFE has plenty of get up and go and could have used a 1.8L 4 cyl and had around 110 hp and been fine.

In fact would have helped with city mpg a lot.

The car has an instant mpg meter that updates damn fast, car is actualy harder to get a high % above EPA but that may just be because it acts differently then the LHS in certain situations ( and my high expectations). My mileage has actualy droped down to about 41 mpg from 42.5 but I just need to find the best BSFC
( http://www.autospeed.com/cms/A_110216/article.html ) for when I'm accelerating, I think I lose a lot of mpg then.

I have a few days off comming up so I think I may try to find a nice long stretch of road to do some tests on acceleration, P&G, and best cruising speeds/throttle possition for various conditions (uphill, flat, highway speed, main road speed, secondary road speed).
My drive to work is too much up and down hill to compare techniques, too many variables to determine best practices.

I will say the speed on the highway seems to have little effect on mpg, going anywhere between 45 to 65 on a perfectly flat stretch of road just maintaining speed I would get over 50 mpg.
First, second, and third gear seem to have cruddy mpg even if just maintaining speed at 1,500 - 2,200 rpm your lucky if you see 25 mpg.
I have just been trying to get to fourth gear as quick as possible while still getting over 10 mpg accelerating to get to the 35+ mpg fourth and fifth gear offer.

Baaah, I'll know more later, I've only had the car 2 days, it will take time to learn it's nuances.

[theholycow]

You can definitely experiment with different shifting patterns. There's skip-shifting (as CAGS in the Corvette and some 4th gen Camaros forces you to do for FE), and just shifting lower with wider throttle. If the XFE has a wideband O2 then you may be able to use WOT + extremely low shifting like I do.

What speed are you maintaining in 1st, 2nd, and 3rd at 1,500 - 2,200 rpm? I bet the XFE has reasonably tall gears, compared to my car being in 5th anywhere above 30 and often above 25mph.