What's your gas mileage?

[JAT]

So I purchased my first car in July of 16 and it was a 2000 Buick lesabre custom. Traded in my 89 Park Avenue as it was nearing its end of life. It had some problems with power locks and the right rear window but all could be fixed, and after all that I love this car! My question now is gas mileage.

Computer said I was getting 16mpg so I had a tune up done with new fuel filter and it jumped up. Recently I am preparing to do some high driving time for work and was wondering what others or I could do to increase my mpg. I purchased new brakes and hankook tires to boot. By my math I have been getting 370 to 400 with city and highway driving. Is this normal? I try to drive with my foot off the gas pedal and I use cruise control constantly. I use shell 87 gas and have noticed in my Airbox the foam that sits between the box and the body was starting to fall in so I moved it/removed the foam that lost its adhesive.

 

[NickaV]

Most I have gotten in my 200 Lesabre was 400 miles from Full to Empty. Usually get around 24 MPG average city/highway combined

 

[OldBettyBuick]

For city miles, i'm at about 13mpg. 1990 Sedan.
I don't have enough data yet to do the combined or highway milage.

keeping the tires inflated to the correct psi will help improve gas milage.
Possibly a new intake airfilter could help too (if this was not done as part of the tuneup).

 

[JAT]

Tires are at 35 psi, and I need to check the filter. For cleaning the air intake and/or maf, any suggestions?

 

[ryenie]

My buddy has an '02 Lesabre, he averages 28mpg mixed driving. And if i'm not mistaken cruise control is harder on your mileage than driving without it, might be more noticeable when driving through the mountains than on flat land but i want to say i've read this in an owners manual some time ago. As far as tune up, i've heard good stuff about lucas fuel treatment and seafoam, couldn't hurt to run one or the other through the fuel system. To clean the sensors you want to use spray specific to that sensor i.e. maf sensor spray for maf sensor. I would add plugs, wires, air filter, pcv valve to the tune up as 16 to me seems really low. Is there a check engine\ service engine soon light on? Might also want to check vacuum lines and connections for leaks, as leaks can degrade your fuel mileage.

 

[GliderRides]

2000 model: 20-22 city/28-32 highway. Best mileage is at 50-55mph, drops to 28-29 at 70-75mph. Better mpg than the 4cyl Honda Accord I owned.

MPG is verified with the DIC, separate trip computer, and ye olde math method. I've found the DIC to be accurate, so I don't use the separate trip computer much anymore, except to read/clear codes.

My trick for cruise control on hilly interstate, speed up a little before the hill, then gradually let the speed drop as you climb, this lets the car top the hill with the converter locked up and in overdrive, in most cases. If I feel the car is about to downshift near the top of the hill, I kick the cruise off to keep it high gear.

When MPG is down and I don't find a reason, I start checking for sticky brakes. Rubber brake hoses can collapse internally and hold pressure for some time after the brake is applied and released. I've found quite a few bad hoses on other GM vehicles.

 

[gnhbodyguy]

You can see in my signature. My kid only gets about 21 in the Custom. I sold the Limited and drive a pickup now.

 

[Lubener]

My 97 gets 21-23 in the city. About 25 mixed, I haven't taken it on a trip of pure hwy so that's still a mystery.

 

[rogersloveboat]

Wow I see that mine likes gas or I have a led foot I get about 15mpg city��
I thought that was pretty good since the vw gti vr6 that I had was a 2.8 and got about the same.

 

[geofjones9]

I keep a book showing every drop of gas, oil changes, repairs, etc. since my '05 LeSabre was new. I was getting 24mpg city in the winter unless we got a real cold snap, then it would drop to 20-worst case. Jan. 2016 I was on a trip to Arizona, got 29.9mpg overall on that trip, just what I expected. Got back home to the Denver area and winter and summer mileage went to 20 in city driving. Replaced plugs and wires, air and fuel filters, cleaned MAF sensor, ran 3 cans of BG 44K injector cleaner through it, had several people hook up diagnostic machine to it & drive. Everything seems great, runs smooth, has power, oil stays clean, etc. I am wondering if the gas has more alcohol in it now, which would cut mileage badly. I and several mechanics are out of ideas. Your thoughts are welcome!

 

[SD73]

I've been seeing gas mileage drops in my cars as well. The only thing I can think that's consistent between them is the low quality aerated fuel we get here in California.

 

[Pop's 2001]

My 2001 (less than 26,000 miles) averages 26.5 both city and highway. I have a slight advantage though as the car was traded into the dealer that I worked for, where it was serviced from day one. Adjusting tire pressure through the seasons has a bigger impact than folks might think. Limiting excessive trunk weight and using the cruise control are advantages also. Frequent oil/fluid changes reduce friction. And yes, Ethanol based fuel does reduce MPG's.

- - - Updated - - -

I've been seeing gas mileage drops in my cars as well. The only thing I can think that's consistent between them is the low quality aerated fuel we get here in California.

During the winter months here in Ohio, we also have oxygenated fuel from certain suppliers which does reduce MPG's.

 

[DUALS]

On my 2004 LeSabre Custom { With absolutely no options } , with 91,000 miles , me being the second owner , on 160 mile round trips { 1\4 stop and go , 3\4 highway } I get 24-25 miles per gallon . Around town , stop and go , I get 16-18 miles per gallon . I've owned it for about six years , bought it with 65,000 miles on it .

 

[DonP]

My old '04 Limited delivered about 21 for suburban driving short trips, and about 28 on flat interstates at ~75 mph. The DIC-reported MPG generally was higher than actual.

 

[geofjones9]

I'm posting a short reply to get this thread to the front page again. No real changes, but after reading what others have posted, maybe I should consider myself fortunate to get the mileage I do. I am still puzzled by the sudden drop at the beginning of 2016. My car now has 193,000miles on it.

 

[Northerner]

my last lesabre 03 and my current 02 have never gotten better then 18mpg and thats figuring it up at gas station. the computer shows around 30 which would be a dream but why is the computer so far off from the real numbers when i fill up? would new injectors help or what? current car has 170k miles.

 

[JayBird]

My LeSabre, a 2002 with almost 190,000 miles, still gets me, on average, 22 to 24 mpg! I do not rely on the computer but keep a gas purchase log for tax purposes. Obviously, my higher mileage is achieved when I do long distance high speed non-stop driving; but the lowest mpg was 21.

 

[2000ltd]

My trip computer on the doc says 30 combined but I get 20 I don't know if something is wrong with my car but I found from this thread that I'm not too far off

 

[DrivenDaily]

Ideally, the more miles and fuel you have to work with, the closer to reality you will come.

For example, if you try to extrapolate the attention span of someone after they've loaded up on energy drinks, but your entire sample is just the first 10 minutes of a 4-hour training session, your results will be heavily biased.

The same with fuel mileage. Drive normally for a few tanks so your stops at long lights and acceleration up long hills will even out across the entire spectrum of how you use your car.

For mine, unless I forget (which has happened), I record all of my DIC data points on the receipt, plus the octane (89 non-ethanol, etc) and outside temperature at the time. (Yeah, it's not the temp for the whole tank, but it's still valuable and valid data.) Routinely, my DIC will say something like the last tank of 30.3 Avg MPG, but calculating it manually ended up with 27.8 MPG. That's an 8% optimistic reading from the DIC! As time goes by, I can usually guess pretty close to the real-life actual mileage based on what the DIC shows me.

I don't always fill with the same pump, and I usually add more until I'm satisfied that it seems to be as full as I'd like it to be. But that can/will throw off the manual calculations since the fuel level at the start of each tank may be different. However, when you spread that across a broader spectrum of several tanks in a month, or many tanks in a year, you can then see where the average mileage on a much larger sample is deflected less by these topping off issues since you end up treating all of those tanks as one big tank and one big fill-up.

For example, if someone were to drive like this:
Tank 1: 450 miles, 15 gallons, 30 mpg
Tank 2: 300 miles, 12 gallons, 25 mpg
Tank 3: 420 miles, 16 gallons, 26.25 mpg

All 3 tanks: 1170 mi, 43 gal, 27.2093123255...... mpg

So, when they get under 27, they are getting sub-par mpg, but above that is above-par. Or you can set your "par" at whatever figure you want.

When you track your mileage, especially if you use a spreadsheet or an app, you can also put those MPG figures on a graph and see it more easily. Then you can even track your changes based on octane or temperature!

All you need is accurate data, and to be consistent by recording it for every tank.

 

[RD_Atlanta]

My (3) LeSabre's mileage are similar to 'Driven Daily's' 2005 Limited. I agree, you really do want to average several tanks.