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Comments
27.5 to 30+ on the highway is great for a 4300# car that is heavy (read mass) and safe by all measurements. In town is 16-18 with lots of variables so not consistent.
I started to post a detailed analysis of gasoline energy but lost it before it went out
Also see:
http://www.ftc.gov/bcp/edu/pubs/consumer/autos/aut12.shtm
which advises higher octane only if your engine knocks significantly.
My 2011 CXS doesn't exhibit knock with 87 RON. Since 93 RON is about 25-30c/gal more (~8.3-10% at $3/US Gal), I conclude high test is a waste of money.
Bottom line: If the car runs well on regular octane and gets the mileage we use it and if the midgrade helps more than the cost we use that (or if the wife says to!)
2017 Cadillac ATS Performance Premium 3.6
I can't agree that if it doesn't knock, go with the lowest grade. There is still a financial calculation to be made. If MPG is up 20% on Super and the price of Super is only 10% over Regular, I'd be nuts to not to use Super. FYI, I have no engine knock on ANY brand or octane. Performance is identical in any normal driving I do or have done.
After the first concern of pollution was tackled, hydrocarbon emissions, they also started learning about noxious nitrogen compounds and many more tactics were employed to slow their production. Retarding the timing was one, hence poorer economy.
Continuing fuel shortages has pushed technology into a very sophisticated engine.
I knew hobbyists that installed fuel injection on their cars during the 60's so that part of the technology has been around. Electronic knock sensors may have been key in implementing today.
Thus we now have high compression engines again via direct injection, leading to better efficiencies and also cleaner burning.
Using too low an octane will cause the ignition to retard to prevent engine damage.
Sometimes I'm confused with GM newer engines. 3.0 & 3.1, 3.5 & 3.6, 3.8 & 3.9. But now that 6 speed trannys are widely available I don't doubt there will be newer engines built that take advantage of that shift range and the way most people drive to squeeze even more economy.
Had a slight red flag the other night. Quite cool and as I eased my foot into it it sounded like it coughed. It definitely lost power momentarily. And I was able to repeat until engine got warm.
Picked up my daughter at the airport yesterday and she was in love with my LaCrosse on the way home. Although she works for Enterprise she'd never seen the CXS as they only carry the base CX in their fleet. Nonetheless, she feels the CXS at over $40K with navigation and the option packages is a bit overpriced.
Daughter's comment is right on loaded CXS price. Cadillac CTS in mid $30's seems like a better buy. Lacrosse in low mid 30's is a great buy with all the necessary goodies. Real buy seems to be Mailbu I-4 and Sonata 4 cylinder for overall cost, features, mileage and true value concept.
I-10 from Houston to San Antonio is mostly a non-cruise control area as too much traffic for safety. West Of SA it becomes a 80 mph posted zone.
From SA to Ft. Stockton, using 93 octane Exxon and cruise at 80ish, I got 25 mpg in the CXS. I use Mobil One oil but otherwise nothing unusual. Tires balanced out at 37 psi after traveling.
Locally in Terlingua it is 2-lanes and all gas tops at 91 octane, not tier one.
Return trip on US 90, a 3 lane road posted at 75 and cruise at 73ish, the car got right at 33 mpg from Marathon to Del Rio on Shell 91. Oil was at 70% life at the start and 56% when returned - an important point IMO.
Car had 2 large adults and a full trunk. Not bad~!
I would like to look into this for you. I would also recommend continuing to work with the dealer so they can try to diagnose your vehicle and take care of your concerns. Please e-mail me with your complete contact information including a good number to reach you, VIN, current Mileage, and involved dealer. I look forward to your response.
Christina
GM Customer Service
Conversation on mileage came up somehow and service writer said they do not even consider MPG complaints until after 5000 miles. Past experience shows that to likely be a real number.
Grain prices are higher in this country than usual world market because of the quality including more of something called gluten, I think. But watch out because number one in his effort to create more trade promised the Chinese grain at over $1 less than current market. I have no idea what the fallout will be but likely more bankrupt farmers at least, or bailouts?
Finally, my son-in-law got Homelink to work, and with that I am now totally satisfied with my CXS.
I will be at my Dad's next week and will give it a try then, especially with zero windchill.
It turns out only the premium has what they call V-Power. All grades do meet tier one though.
http://www.shell.us/home/content/usa/products_services/on_the_road/fuels/shell_v- power/about_vpower/
It might help with deciding to use regular, mid, or premium at a Shell fill-up. The link extolls the benefits of using V-Power (premium) over even the lower grades of Shell.
My point was that they claim their premium contains extra amounts of additives, more than their other grades that still meet tier one. I saw no such claim on Chevron site, but when is clean clean enough?
Chevron has had Tecron for at least 20 years and they claim nitrogen enriched. Unless they changed its formulation recently, maybe they were ahead of the rest. Makes me wonder if Shell is buying additive from Chevron?
Daughter has truck that she has been ignoring for many years. I got involved when a busted thermostat housing surfaced at 185K miles. Actually a couple of months earlier because she had been driving for at least 6 months with check engine and gas cap lights. I fixed the evap air leak and EGR code problems and gave her a list of needs.
I noticed it was idling rather rough after full coolant system work and seemed to not be quite right when cruising around 50MPH. I learned her gas buying was whatever is cheapest. Not having expensive computer diagnostic I had to work with what clues I had, EGR was non-functional for at least 6 months, cheap gas, prematurely dirty oil, and that plugs and wires were done only a couple of years earlier.
To be on safe side and maybe clean up some of the internal gunk I used oil known for its cleaning ability and factory filter which was much larger than that quick change place. Told her to watch oil changing at every fill and hope it does what it can.
Pulled sparkplug. OMG, it must have been shade tree mechanic. No silicone so boots release from plug. No anti-seize on threads and plugs were very difficult to remove. Also they were the wrong plug.
I had only pulled one which showed no wear but because of the above I decided they needed changing. I put it back in so I could work on a bit more cleaning without damaging new plugs.
Ran most of a can of GM intake cleaner through it followed by Seafoam. Found excess oil around PCV valve and changed because I'd bet it was original one.
Proceeded with sparkplug change. Oddly four of them showed extreme wear, none platinum or other high mileage type. The two with no wear were paired with two that had wear.
I find this odd since this is a system where two fire simultaneously. What gives?
Also replaced O2 sensors hoping to optimize a bit when it went to closed loop although rough symptoms showed in open loop.
Both idler pulley bearings were also going and replaced pulleys.
Test drive showed drastic improvement. Shifting became more precise with mild acceleration. I think the computer was having a hard time determining if the proper amount of torque was present for shifting because of weak running engine as it tried to lean out properly. Also the engine was much quieter as well as smoother.
It still seems to have idle in neutral issue. I do not have equipment to reset computer so it may take time to relearn what is needed at idle or it may be a quirk of this engine trying to lean as much as possible and constantly being in the hunt for that spot. Or maybe it is time to get rid of those non-OE plug wires.
And final instruction to her was start using tier one fuels, ONLY. Add bottle of Techron to first tank, the one for cleaning up system, the most expensive version. I am quite certain her husband got it wrong and used the one for cleaning injectors only. So to avoid confusion I asked her to fill with Shell Premium next time and hope it finishes any cleaning necessary.
Sorry that I'm going into another vehicle but it has valid points.
Be careful who does your work
Use OE parts unless you have a really good reason not to.
Pay attention to the fuel you use.
Try to learn of recalls and TSB's on your own. If she had they would have replaced the first and second planetary gear sets in the transmission for the whirring sound they make until 100K, if she had complained. It would now cost her a couple of thousand.
And check what parts your dealer is using. Likely safe under warranty because I think they have to return parts for credit. AFAIK, dealer service is not bound to use OE parts only. I have been in the parts area when other distributors were dropping off parts.
And on one of my previous vehicles there were numerous posts about that Northstar engine not liking aftermarket parts, even something as simple as sparkplugs.
I have had intermittant (one in ten starts) clanging IMMEDIATELY upon starting....when I used non tier 1 Regular gas. With Shell Premium. I haven't heard it in the last twenty five starts. Keeping my fingers crossed. My guess is that the computer checking the knock sensor takes a second to come online after a start thus the timing is not yet retarded. In daily driving, there is no knock and performance seems normal. Gas mileage is better with Premium and the cost difference does not exceed the gain..so Premium it is in my 2010 3.6L
Too bad dealers don't have the good sense to ask about fuel when they hear this clanging compalint. One guy even had his exhaust system changed. Probably a coincidence. Maybe the dealer felt bad after the third trip and filled his tank for him...with better gas!
I won't rule out the release of the starter mechanism since it occurs at precisely the moment start occurs. And if related to that it could tear up the ring gear on the torque convertor. That would be horrible news since it would need tranny pulled.
Does yours do it at the very moment engine starts? That is why I question that the starter may be involved. I do not know how this automatic start is set up but it could be the power to it is killed the moment engine RPM reaches just the point of running. And an improper release of the starter gear could be involved. Sometimes the starter motor has to be shimmed to acheive proper meshing of the gears. Improper mesh if not close enough could cause premature wear. Too close could cause binding resulting in late release or even no release. I hope I'm shooting in the wrong area but bring it to attention because the consequences could be far worse than just noise from exhaust pipe. And the down the road repairs would be far more expensive. If I can get at it, I will mark starter bolts to make sure they don't tamper with that and then neglect to tell me. As said, damaged gears could be major down the road even if shimming or adjusting does the immediate fix. BTW, starter is not part of powertrain coverage and not sure what they would say if starter gear damages ring gear on torque convertor.
Has it come back on those who have had pipe change?
Is it possible something was moved, loosened, retightened, etc. during the work, other than the exhaust itself?
How much of it from the front was changed? Did it include the pre-converter right off the exhaust manifold? Possibly a defective weld in the system such as where pipes join other components or the seams on the converter. From what I've read that first one lights off almost immediately. That is, it is hot enough as soon as the engine starts to function unlike the ones further downstream.
Sit back and enjoy the ride. I do.
If I had as many issues and suspected problems as you are having with yours, I'd be at the dealer's every day looking for "lemon law" rectification.
My favorites:
Infiniti M56X, the seats are the best I've sat in and everything is just well laid out. The exterior styling is forgettable though.
Lincoln MKS, wow! Big, powerful, refined and full of technology...it even reads text messages.
Jeep Grand Cherokee--without a doubt, the best designed and refined SUV out there. The fit and finish and quality of materials are beyond anything Chrysler, or for that matter any manufacture has offered before.
Buzz:
Nissan Leaf -- smaller than expected, the car was locked so we could not touch the interior instruments or surface material quality. Nice cockpit and well laid-out though.
Chevy volt -- looks good from a distance as we couldn't get near enough to touch it.
CTS-V -- I saw middle age men salivating over themselves
Camaro -- In lime green it raised the testosterone level of teen boys about 20-fold
Kia Optima -- best new exterior styling this year. The proportions look perfect
Disappointments:
Equus -- looks lethargic, dated styling inside and out. High quality materials on door and seating surfaces.
Honda and Lexus -- nothing new, generic styling, in short boring cars.
Low gas mileage on most vehicles, 17/24 mpg seemed to be the norm
Surprises:
Such little attention the Buick brand received, not even the Regal raised an eyebrow.
Very large crowd at the 5-day show, although we are supposed to be in a recession. Oops! I forgot, the recession is over.
FWIW, I checked my oil yesterday and it looks really clean and up to the top, even after my long road trip. Rings must be seating pretty well. Had the car now almost 2 mos.
The Lacrosse is a great assembly of parts and design team efforts - THANK YOU Bob Lutz- before the phone guys at new GM marginalized him for excessive knowledge of the car business that made the outsiders look out of touch. Lacrosse, Malibu, CTS-V, SRX, Regal (Insignia clone) and other decisions were made years before the Chapter XI filing and the sacking of Wagoner and his team of old GM insiders that were stuck in the push model of the past past. Bob Lutz pushed for and got support for competitive designs that now sell well for GM.
Sit back and enjoy is good advice for all of us. We s/b thankful to be able to afford a new car in these difficult times.
Happy Holidays to all on this great board with VERY useful information on our cars.
If you are comfortable, you can open you hood. Then sit in the driver seat and start the motor. After it runs a minute or so, turn the AC from OFF to the ON position where the AC light is turned on. If the compressor is turning on, you'll hear a metallic soft "thunk" as it engages.
Or if you know where the compressor is on the belt system, you can look at the center part of the pulley while the engine is running. If it's turning with the outside of the hub that the belt wraps around, the compressor is engaged. If the center is stationary, the compressor is not pumping freon.
2014 Malibu 2LT, 2015 Cruze 2LT,
BTW, it just hit me. The improvement in my gas mileage is due to the compressor being turned off during the cold weather rather than the higher 93 octane or purported engine break-in.
As to the AWD: suggest you do your own research. just seems to me that having "normal" tires on the vehicle as opposed to "mud/snow" traction tires, would make a BIG difference in the ice/snow. Ask your "dealer" to show you the tires on his/her vehicle!
A lot depends on the roads and their maintenance. Consider how remote the roads are you travel. For me, help is usually nearby.
By the way, is it me or the new setup that does not allow cutting and pasting? At the beta stage all features appeared to have worked flawlessly but now I am noticing several hicups including the inability to edit a post.
My gas mileage has deterioated. On my previous tankful I got 20.91 mpg but today, with my most recent fill-up with Shell octane 93 V-Power I got a disappointing 17.5 mpg. It is the true the weather has been unseasonably cold but that is a big drop.
And today I had a pleasant surprise. I took my CXS to a Chevy dealership because my tire pressure had dropped to 32 psi in all tires (yes the weather is really cold out there). Almost everyone in the service department rushed up to take a look and sit in my car. Their reactions were unanimous..."wow what a great car!"
Sorry for the boring update but there is nothing to report really. The car just works flawlessly with the heater keeping my cabin at a comfortable 73 degrees. How sweet. BTW, after five months I'm still having issues with parallel parking. The combination of the high rear deck, sensor and back-up camera can be a little disorienting at times. Nonetheless, a great car and I have no regrets switching from the Avalon to the CXS.