Buick LaCrosse: Real World MPG

beyrer

try getting your car greased that should reduce the noise

beyrer

i have a 07 and im hear to tell you thats just the way the car is .........it is a very tourqy car i have tyed to manipulate the gas pedal to no luck when you stay below 2,000 rpm's the car does not even move sorry

bobinor

So we were directed here by moderator Kirstie. That makes little sense IMO as these posts are all about older model years.

Anyway, I have copied my post #1263 from the 2010-2011 Buick LaCrosse thread made on 11/19/10. There are quite a few other posts there regarding mileage experiences of 2011 CXSs and CXLs. Here goes:

I probably won't be as complete as bwia but here's my attempt to gauge the gas mileage of my 2011 LaCrosse CXS on a 1600 mile road trip this past week.

My trip was from just south of Portland, OR to San Jose, CA returning to Portland from the Cailf. gold country in the Sierra foothills at Angels Camp. (2 days of great golf in shorts at Greenhorn Creek GC) Starting mileage on car was 624 so I was trying to be careful to not exceed the 68 mph break-in guideline. Typically, I set the cruise control to 67 mph on all freeway stretches. Yeah, it did go over for bursts.

Total miles: 1586 with average gas consumption of 27.177 mpg

I used mid-grade tier one exclusively: Shell, Chevron and 76. I checked and filled my 19" tires to 35# before leaving home. There was very little wind on any of the legs of the trip. Anyone who knows the route on I-5 between OR and CA knows the grades and dips you encounter. Siskiyou summit is ~4500 ft. Then there's Stagecoach Pass, Sexton Pass, Mt. Shasta, the Sunol Grade (2X), etc., etc. Just to give you all a sense of the elevation change challenges in such a trip that defeats great gas mileage that you might get in say, the mid-West.

Speaking of mid-grade gas, the octane for such in Calif. is 89. In OR it is 91. Huh!

The car was stuffed stem to stern. I thought I'd have a challenge getting as much as I wanted into the trunk. But that got filled to the brim and the rear seats were loaded, too. So I was able to take my wife in the passenger seat (creative packing = good move!).

Best leg: Red Bluff, CA to Sunnyvale,CA 222 miles on 7.396 gals. = 30.016 mpg

2nd best leg: Farmington, CA (near Stockton) to Rogue River, OR 386 miles on 13.048 gals. = 29.583 mpg

Worst leg: driving within Silicon Valley,CA 4 days and then to Angels Camp with sightseeing, 288 miles on 12.896 gals. = 22.333 mpg

Overall impression: I'm thrilled! These results far exceed my expectations for highway driving. I received numerous compliments along the way about the styling of the car which went a long way towards helping me see my way to the next car payment. The car is as much a cruiser as any other on the highway - a dream to drive! It handles nimbly (can I say that?) on mountain roads with sharp twists and turns. I love it!

I'm sure I've left out some pertinent details I intended to convey but wanted to post this on the day we returned. If I think of those, I will post them later.

Kirstie_H

You can also go to the general 2010/2011 LaCrosse discussion - we just don't have enough owners around here to support a separate discussion for each issue on each model year.

bobinor

Ever being the miser, I filled the tank of my CXS this morning to avoid spending an extra .07/gal when a new state tax takes effect tomorrow. Gas consumption for 113 miles was 15.07 mpg. I still have under 2500 miles, total.

Here's how those 113 miles were accumulated:
About 46 miles were for a round trip from home to the airport in stop-and-go traffic one way.
The remainder were short trips to stores, etc. of less than 8 or so miles each. Those trips involve getting me back up my hill which is .8 miles of straight up, .4 on a 22% incline. At the bottom of that hill there are a number of ups and downs, too, to get where I am going.

My main point is that while I was very satisfied with my road trip mileage, the in-town driving in our terrain is going to drag my overall experience way down. I knew this would be the case but wanted the CXS for the road trips, primarily. We use our 4 cyl. Equinox for most of the local driving but I just can't resist taking the CXS out every now and again as it's such a pleasure to drive in all other respects.

Truly, YMMV. Happy New Year!

cooterbfd

Bob, I don't know if you check your FE against what the trip computer says, but I find that my trip computer gives a very conservative estimate of FE.

bobinor

I don't quite understand your point. I reset the trip #1 counter in the DIC at each fill-up. I've never touched the Average Fuel Economy display to reset it. So I use the tried and true method of trip odometer miles/gals. pumped in all my mpg calculations.

cooterbfd

That's what I mean. For example, if I go 200 miles and the avg econ says 20.0, when I go to fill up, I find that it only takes a little more than say 9 gallons.

e_net_rider

I check mine both ways and usually the DIC is a little low, but sometimes it is the other way.
It may have something to do with the accuracy of the pump which is beyond our control.

bobinor

Well if we're going to doubt the accuracy of the pump you have a case for the D.A. to pursue. I would trust the pump and my odometer before I put any stock into the fuel economy display in the DIC.

e_net_rider

A few years back, DateLine, I think, did a piece on how cleverly they can short you at pump. Some were using a remote control device that worked from inside store. A normal state check of pump accuracy would never detect it. To find such they had to use undercover people and when they suspected something was wrong they had to tear the pump apart to locate what they were doing.
Hopefully they have found a better way of monitoring.

As to the accuracy of the DIC, I don't understand just how they calculate the fuel usage. It might be the summing of the time the injectors are on and assuming accuracy of pressure regulator. Some regulators vary the fuel pressure with the manifold vacuum and don't have a sensor that measures that vacuum so it would seem they have to use a combination of throttle position and engine RPM to derive the fuel pressure.
I had one such regulator that the diaphram developed a leak to the vacuum line and that was feeding fuel directly into the intake like a carburator system. Other sensors picked up on that as running rich and leaned the injectors. Thus the measured fuel as indicated by the DIC was much less than actually used.

cooterbfd

I try to look for some constant in the whole system. On my old Park Ave, I noticed that regardless of where the pump clicked off at first, is was generally near the gallons used reading if I added a little more. However, if I tried, I could always "top it off" with an extra gallon or so. I never felt comfortable with that. I felt as if the "constant" was the Gallons used gage.

On the Lacrosse, I notice that the car seems to have been designed so that "topping off" is imposssible. When the pump clicks, I can never put in more than say a quart of gas. I don't believe that this "first click" is entirely reliable, but is the "most constant" aspect of the fillup. I always find that the FE is consevative as opposed to "doing the math" with pump gals/trip odo.

I also think that on short trips, the FE indicator "overcompensates" every time you shut down and restart the engine.

e_net_rider

For many years the evap cannister how now been used. Topping off by pushing beyond the first shut-off was found to cause problems with that system. Sometimes fuel, not vapor, would saturate it and muck it up. Sometimes it happened by overfilling and then fuel expanding in tank causing the same effect. That is why they now have instruction to not fill beyond the first shutoff.
They many have added extra protection explaining your experience.
Usually there is some ground slant at pumps and I always pull up so the fill cap is lowest. That is to avoid issues with evap system and also an effort to fill to the same point consistantly.
Granted, some shut-offs are more sensitive than others but they seem to be getting better in that area.
Not sure what you mean by over compensating?

cooterbfd

".....Not sure what you mean by over compensating? "

What I have noticed is that when I shut it off, it reads one reading (say 21.3 for argument's sake). When I get back in and start it, it will read 21.1 or 20.9, without ever having moved or idled.

Right now, it reads 18.4. I have approx 200 miles on the trip, and doubt I have used more than 10.5 gals. When I leave work, I shall fill it and see what I get.

crankeee

Rainman: We experienced the same change in MPG using Shell midgrade. Can't say if it is the "Shell" or the higher Octane that retards the ignition level to accomodate the higher compression engines. Whatever it is the mileage is improved at all speeds with obvious max at 55-65 MPH (32 to 30MPG). 75-85 MPH drops to 29 & 27.5MPG that makes sense. All numbers with two passengers light luggage and fairly normal weather conditions. The computer on ours is very close to actual calculations so we are skipping that step. I believe the new 3.0/3.6L series V-6 prefers the higher octane fuels due to the higher compression ratios and the prom/computer program set up for mileage and nor low end torque/speed, but would be hard pressed to prove it with logic or math!
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

cooterbfd

BTW, I used 10.8 gals for 216 miles, or about 20 mpg It built up to 19.2 on the screen.

ar15

I have only 3071 miles so far, but I've checked the gas mileage at almost every fill up.

On an all highway run at 72 mph, I have slightly exceeded 30 mpg.

I'm averaging just under 25 mpg with about a 60/40 mix of city/hwy driving and a slightly firm foot on the accelerator.

crankeee

ar15: Excellent mileage for a 4400 # vehicle. We were VERY curious about the actual MPG for the I-4 after the switch from the 3.0L V-6 base engine. We have the 2010 CXL with that 3.0L engine and have been most happy after ~9500 miles- mostly highway so far. At 70-75 MPH we see 29.4 MPG as al ong term average on the highway. Greater spped reduces it to 27.5 or so. The big diiference is the city MPG probably. With all city we see 20-21 at best and sometimes lower with conditions. Again, not bad for a 4400# vehicle that drives like a breeze!
We wanted a new car with ~30 MPG on our many road trips and the Lacross in either form has delivered for all of us. Great car!
Thanks for the post & good luck. Enjoy the new car.

e_net_rider

I don't know why?
That is I was expecting better mileage from CXS with 3.6L, simply because of engine improvements.
Maybe pollution standards have impacted.
I was seeing very similar mileage in 96 Olds Aurora with 4.0L V8. Slightly less on my local driving, but hard to beat smoothness of a V8.
And now being in loaner Regal with I4, I'm not impressed with what I see the guages showing me. Less mileage than 09 Malibu with same drive train.
And appears to be about the same as I was getting in 93 Regal with 3.0L and 4 speed auto. That vehicle was checked repeatedly on highway and high speeds would show about 29 MPG. No 24 valves, DOHC, VVT, DI, etc., just SFI, sequential fuel injection.
So, what gives?

ar15

I just completed a 2100 mile trip with my 2011 CX (4 cyl) and averaged over 30 mpg. The trip was 95% highway driving with cruise on between 70-75 mph, 3 adults and a trunk full of luggage.

I'm averaging about 27 mpg combined city/hwy for my normal driving.

crankeee

Thanks for the feedback. I was curious about the I-4 on the road. We have the 2010 CXL with 3.0L V-6. 28-29.5 on the highway but low 20's in town. That seems to be the major diff - the city MPG. The 3.6L MPG posted by others is also diff. due to more HP I guess. We wanted a car with 20/30 and feel we got pretty close. most of our miles are highway so we are pleased with our choice. sounds like you are also.

ar15

I'm a muscle car guy and like lots of power. My 4 cyl LaCrosse was provided to me as a company car. I just can't believe how well this car performs with a little 4 cylinder. For a car of this type (family sedan), I honestly don't see why anyone would feel like this car was underpowered, or would feel like they need any more power. After driving it, I just could not justify paying more for a v6.

e_net_rider

Thought I'd chime in because of the suggestions to reset MPG while cruising in lieu of having INST MPG on the vehicle. I tried it the other day. There is no way that can give an accurate reading.
Cruise locked at 60MPH, it was jumping up and down like a yo-yo for the 20 miles I checked. Although still jumping around a bit, it looked to be around 25.8 MPG. On the return run, once I got to the interstate again, I locked at 65 MPH. Again it jumped all over the place and started to settle some past 20 miles. I was in cruise for about 35 miles and the display was showing 32.5 MPG. BS for sure. The only conclusion I could possibly derive is that it possibly get better MPG at 65 MPH than 60 MPH.

e_net_rider

Sounds like you are happy which is number 1.
And because yours is basic, you won't be having some of the headaches, but watch out for basic issues such as sticking caliper, etc. :blush:

crankeee

ar: We had a 350 HP 327 Chevelle, 69 Olds 442 and a 90 300ZX so we enjoy the power side also. the new Lacrosse with either engine choice is a great car IMO. I-4 was not available when we bought our 2010 CXL. The 3.0L V-6 is actually a pretty small displacement but was well matched to our cars weight and 6-speed so performance is great. City MPG is much lower than your I-4, highway is comparable. We paid for ours (no co. car) and feel the value is outstanding vs. other models.
Enjoy the car.

e_net_rider

Just chiming in. The 3.6L has more than sufficient power even if categorized as luxury sport or family sedan. I don't know the full capabilities, but my salesman told me he had had one up to 140 MPH. I certainly hope he was not test driving mine. It takes a lot of power to push one that fast and said it had more to give. I will say at speeds not near that fast, it is fairly quiet and well on the road.
And at upper speeds the joggle and sway seems to disappear. That is just great. You have to drive it at speeds of big tickets and gas guzzling to realize some of the features of the vehicle.
I certainly think some dunder-head needs to be removed from the ranks of GM. They must think more power will sell more vehicles with the 2012 change for this engine. It was probably cheaper to squeeze more power than to make it more efficient.
I do have to wonder if some old rules of durability start to come in with the vast difference between 2.4L and 3.6L. Going back just a couple of decades, I4 did not last as long as I6 and that did not last as long as V8. If you were unfortunate to have one of those aluminum I-4 from the days of Chevy Vega, you might make 50K and that was with a lot of oil and dead mosquitoes. (They did use a cast iron block in some and that was quite durable)
What I'm getting at is the final drive ratio. Will the V6 outlast the I4? If we went back a number of years, for some reason Volvo had I4 that would outlast a lot of engines. Yet, today you can even get a V8 in a Volvo when such was not available years ago.

It certainly brings questions of how they will address the now getting close MPG requirements.
I'd heard the big rear wheel drive of Ford is gone. I questioned an officer wondering what they'd do. They apparently have tried some of the Dodges and are not happy with them from dependability and durability perspective. He told me that there are none better than the crown vic, not even a close second. So police are advance buying large quantities of them into storage. I don't understand why, but they want rear wheel drives, he said.

ar15

I don't think the 4 cyl will reach 140, but I had mine up to 107 easily. The fact is, the 4 cyl has enough power (IMO) to satisfy 90% of the buyers of this car.

Back when 4 cylinders were only lasting 50K miles, owners of v8's were lucky to go past 100K without needing major engine work. Today's engines are typically the most reliable part of a car, and it is the accessories (AC, auto transmissions, brakes etc.) that break down and and cause so much expense to repair. If an owner changes the oil and keeps his vehicle maintained, this 4 cyl should go 200k easily.

And at highway speeds, the 4cyl is typically turning between 2500 and 3000 rpm's .

bobinor

I took great pains to measure my MPG on my latest trip from Portland, OR to Silicon Valley, CA - a trip of 655 miles on freeways over mountain passes and through valley flats. On the return trip, which did not include any city driving (but we did get caught in a traffic jam on the I-5 freeway caused by exiting fans from the OR vs. OSU Civil War football game yesterday), we got 27.03 mpg. On the trip down of 678.6 miles (I had driven at home for a bit before we took off) we got 25.99 mpg. Perhaps different lengths of uphill grades on the trip south accounts for some of the difference (1 mpg). Overall, with a side trip to Angels Camp and back to Silicon Valley, the entire trip with lots of short shopping trips within Silicon Valley over 1 1/2 weeks, we got 26.06 mpg for the 1507 miles we put on the car. The trunk and back seat were fully loaded and my wife and I were the occupants. I did the only driving. As a result I am fully satisfied that my 3.6 V6 is delivering as advertised (27 mpg highway). I have a total of 9365 miles on the car purchased Oct. 2010. And I'm lovin' it! Did I mention the comfort on these trips? Oh yeah!

emb140

Seeking real world MPG for the 2012 Buick Lacrosse e-assist.

crankeee

bob: we confirm your expereince on our 2010 CXL with 3.0L V-6. At 65 MPH the car gets the best highway MPG at 29.8 on 700 mile trip. 75 MPH drops it to 27-28 or lower with all hills. If spped is kept at 65-70 and the terrain is flat the cars seem to get the best MPG. Great for a heavy VERY comfortable car. We just bought a 2012 Sonata to replace a 14 year old GM model. Only 500 miles but the highway MPG is outstanding. Very light car with I-4 non turbo engine but a very good value and so far seems to exceed the 24-35 EPA MPG rating. Two different cars but that is what we needed.