: Anyone have any tips on mods to improve gas mileage??



LuciousLAC
03-19-12, 11:09 AM
I get about 16 mpg which i think is average. About 275 miles to a full tank. But i just feel like im gassing up a lil too much. with gas at $3. 60 a gallon i wanted to know is there any mods to improve this?

MoFex
03-19-12, 11:23 AM
Sorry to disapoint you but there is nothing you can "modify" except your driving habits.....I am getting 20 mpg suburbia driving and 25 - 28 mpg on the highway. However, when I push it a bit harder the gas milage suffers....it is simply physics at work....

LuciousLAC
03-19-12, 12:19 PM
I see u are in atlanta so i guess u really feel my pain. im in augusta. ahh well i guess thats the tradeoff for having a 3.6 DI!

i still love my purchase!

kingtj
03-19-12, 02:02 PM
Yeah... Even when I'm driving a fair bit of highway miles (to and from work, etc.), and not driving aggressively at all around town, my combined mileage never seems to get above around 17-18MPG, at best.

(I'm driving the 2011 CTS Coupe AWD.) If the "instant mileage" readout on the DIC is to be believed at all, it looks like the *only* way to get decent mileage in this vehicle is to coast as long and often as possible. As soon as you press the accelerator down at all, the instant mileage drops like a rock, to as little as 3-4MPG!

Bottom line is that this is a very heavy car, so mileage just isn't going to be too impressive. Personally, I think the EPA highway estimated mileage numbers they published are suspect too, but maybe I'd actually see those in the right conditions, on a LONG highway drive using cruise control....

Truthfully, if I knew the gas mileage on these was quite this low on average, I might have been more motivated to find a used CTS-V Coupe. I'd love to have the V, except I feared car insurance would be sky-high, AND the mileage those guys were reporting (around 14MPG?) put me off as well.


I get about 16 mpg which i think is average. About 275 miles to a full tank. But i just feel like im gassing up a lil too much. with gas at $3. 60 a gallon i wanted to know is there any mods to improve this?

MoFex
03-19-12, 02:15 PM
I drove several times to Florida, always on the same interstate, similar speeds an dguess what? The fuel economy was anywhere between 24 mpg - 28 mpg. The largest influence was the wind. During my second last trip I go 28 mpg arriving in Tampa, last one - 24 mpg arriving in Fort Myers. The difference? During last trip we were going against head wind, that gusted up to 30 mph.....

So I do believe in EPA hwy ratings.....

And yes, this is the price we are payng for luxury (car weight) and performance - 3004HP ;)

Wag-O-Neer
03-19-12, 07:17 PM
Just this weekend, I got the car up to speed on the highway, set cruise to 69MPH, and zeroed the MPG indicator. After 33 miles of unimpeded driving, I was getting 20MPG. They lie....

jimtreber
03-20-12, 02:06 AM
I, too was disappointed in the mileage on my 2008 CTS DI AWD. I traded in a DeVille Northstar that easily got better mpg.
Last week I bought an Airaid cold air intake package that included the throttle body spacer. I originnaly scoffed at the spacer ads about increase torque and mpg even after reading tesamonials. 4 days ago I installed the spacer only, saving the intake system for another day. It took me about 10 minutes to install.
I am now a believer. I could feel the difference the minute I left the driveway. I've been watching the average mpg closely and my driving consists of city and suburban driving My mpg increased over 3 mpg on a 4 day average. I have yet to make a hiway run. Unless there was something wrong with my car to make this difference, this thing works for me. I hope there is no downside.

00 ss
03-20-12, 10:33 AM
Mine averages just under 22 mpg in my normal commute. It's a 100% stock 08 AWD DI car. I'll be taking a long driving trip (900+ miles each way) starting Thursday so by next week I should know what the true highway mileage is. I'm hoping to see 25+ but I'm not holding my breath.

Tell me more about this Airaid product. Do you have any pics?

Edit:

I went and found the Airiad product on their website. They state that the increased air velocity improves fuel atomization. This has some chance of working on a standard fuel injected engine, and even more of a chance on a throttle body injection system or a carburetor. But in the DI engine, air velocity has no effect on the fuel atomization since fuel and air don't mix until it's already in the combustion chamber. The unit for the 3.6 also appears to extend into the throttle body. I can see this increasing air velocity by reducing the area of the opening out of the throttle body. This may indeed produce better off idle response, but it will likely hurt higher RPM performance.

Jimtreber, it appear you have been using this product for about a week. Please let us know if your gains appear to be sustained after you've used it for a few weeks or months. It may be possible that your increase in MPG is actually due to you watching the monitor and unconsciously altering your driving style and not from this product. Then again, maybe it actually works and there is some bit of physics and thermochemistry I'm overlooking.

Mano4
03-20-12, 03:59 PM
I currently installed the Injen Cold Air Intake and have had it for about 3 weeks now, it has increased my fuel economy by a quarter of a tank, and I mostly do city driving.

00 ss
03-20-12, 05:53 PM
So you're saying you got 25% better fuel economy by installing a new intake tube and cone (or cylinder) shaped filter located down lower? That would be an increase of about 3-5 mpg in the city. If you can sustain that for extended period of time, that would be truely amazing. I hope you can. Would you mind resetting your average fuel economy setting on computer and report back on your average MPG after a couple more tanks?

LuciousLAC
03-20-12, 06:35 PM
I currently installed the Injen Cold Air Intake and have had it for about 3 weeks now, it has increased my fuel economy by a quarter of a tank, and I mostly do city driving.



Well so far i hear mostly that a cold air intake is the best way to go to improve gas mileage. HAs anyone ever heard of those gas saver things the sell on ebay. something about they use negative ions on the gas and make your mileage better.

Any truth to that?

00 ss
03-20-12, 07:56 PM
I've heard of them, but I've never met anyone who could substantiate the claims. I am very skeptical of them.

jimtreber
03-20-12, 11:44 PM
Mine averages just under 22 mpg in my normal commute. It's a 100% stock 08 AWD DI car. I'll be taking a long driving trip (900+ miles each way) starting Thursday so by next week I should know what the true highway mileage is. I'm hoping to see 25+ but I'm not holding my breath.

Tell me more about this Airaid product. Do you have any pics?

Edit:

I went and found the Airiad product on their website. They state that the increased air velocity improves fuel atomization. This has some chance of working on a standard fuel injected engine, and even more of a chance on a throttle body injection system or a carburetor. But in the DI engine, air velocity has no effect on the fuel atomization since fuel and air don't mix until it's already in the combustion chamber. The unit for the 3.6 also appears to extend into the throttle body. I can see this increasing air velocity by reducing the area of the opening out of the throttle body. This may indeed produce better off idle response, but it will likely hurt higher RPM performance.

Jimtreber, it appear you have been using this product for about a week. Please let us know if your gains appear to be sustained after you've used it for a few weeks or months. It may be possible that your increase in MPG is actually due to you watching the monitor and unconsciously altering your driving style and not from this product. Then again, maybe it actually works and there is some bit of physics and thermochemistry I'm overlooking.

I totally agree with you and even hesitated to rush a post here before the true facts and certainly do not want to misslead anyone. But the difference was dramatic enough to speak up. Feeling the difference in the go pedal did make me wonder if it was in my head. Before the spacer I have been trying to ease my mpg dissapointment by driving this car in a way trying to get the most mileage so I know what it will max out at with me behind the wheel. While I feel that it takes less pedal to do the job now(or may be my imagination), I may now be driving it even a bit harder because it seems to pull better at light throttle. Before I install the cold air package, I want to do a few hundred miles on the interstate and see what happens there. Like I said earlier, for all I know there possibly could be a problem with my car accenting these results. But it's making me happy.

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00 ss
03-21-12, 12:13 AM
Well that's awsome. What mpg were you at and where are you now? When you get a chance, I'd be very interested to know if the increase carries over to the highway.

It sounds to like you were as skeptical as I am before you tried it. It's still hard for me understand how such a simple thing could do so much and NOT be included from the factory. You would think that the factory would WANT to install something like this if works that well.

WRXtranceformed
03-21-12, 11:53 AM
Another easy "free" mod you can do is to not carry around a lot of extra weight in your car. Don't leave stuff in your trunk, remove engine covers / hood heat shield, remove the spare tire and replace it with fix a flat, etc.

Other than that, driving style is a big one and keeping up on your maintenance is another.

LuciousLAC
03-21-12, 04:07 PM
Another easy "free" mod you can do is to not carry around a lot of extra weight in your car. Don't leave stuff in your trunk, remove engine covers / hood heat shield, remove the spare tire and replace it with fix a flat, etc.

Other than that, driving style is a big one and keeping up on your maintenance is another.



I highly doubt anyone will go to that extreme of taking the spare out. And i hear fix a flat is internal murder to tires!

WRXtranceformed
03-21-12, 04:20 PM
I did it in my 07 TL Type S and it was no problem. In fact, didn't some of the CTS's not come with a spare but came with a similar type fix a flat from the factory? I seem to remember seeing that.

I have not heard that it causes damage to tires, but I have heard that mechanics get pissed if you don't tell them you used it when you change the tire.

sandcracker21
03-21-12, 04:59 PM
I've heard of them, but I've never met anyone who could substantiate the claims. I am very skeptical of them.

No. These do not work.

Do you think Cadillac/GM would NOT put a $10 part into their cars that would make them more appealing to consumers via better mpg?

And an aftermarket CAI MIGHT give .5 mpg increase at most

Mano4
03-21-12, 05:35 PM
yeah i can deff do that, the car is in the shop right now getting a paint job but I should have it back tomorrow.

jimtreber
03-22-12, 01:48 AM
Well that's awsome. What mpg were you at and where are you now? When you get a chance, I'd be very interested to know if the increase carries over to the highway.

It sounds to like you were as skeptical as I am before you tried it. It's still hard for me understand how such a simple thing could do so much and NOT be included from the factory. You would think that the factory would WANT to install something like this if works that well.

I finished a tank of gas and I'm still at 21.2.
Previous best for the same route, 18.2 (city/suburban).
During this tank of gas a 40 mile interstate 70mph run bumped it to 22.2 without resetting. Afterwards several 10 minute local trips dropped it to 20. Now it's back to 21.2. I didn't think to track how many miles I put on and I'm driving lightly. I'll reset and take a long interstate run shortly although I don't have a base to compare.

Mano4
03-27-12, 01:33 AM
I averaged 20mpg on my last tank and it was strictly city miles. just driving to and from work stop and go type traffic.

amunderdog
03-27-12, 02:02 AM
Getting 22 to 24 MPG out of old OBD-1 Northstar power:)
Bummer to read the latest greatest is not doing better.
Maybe you could get the computer programed to economy?
Dear Leader says:

http://www.youtube.com/watch?v=nB8VgInZ4DU

00 ss
03-27-12, 08:15 PM
I just completed a 2200 mile road trip. The best single tank mileage I got was 25.7 mpg over 320 miles from Flagstaff to Albuquerque. If you've ever made that run, you know it's mostly down hill. If it weren't for the wind, it might have been better. Overall average for the trip was right at 24 mpg. Some qualifier to these numbers, I had the cruise control set at 83-84 mph for most of the trip, gotta love 75 mph speed limits and I had the trunk full of luggage and my wife and both kids in the car. I may have been able to get above 25 mpg on the overall average if I had been going slower.

I still 100% stock.

mirekj
04-05-12, 07:55 PM
FYI, I just picked up my 09 awd di premium and do nothing but highway miles every day. average about 200-250 miles a day. I will get at least 26-27mpg @ 72mph on cruise all day long here in Illinois and Wisconsin and I noticed 1-2 less with the air conditioning on. Its been about 5 tanks worth so far, and I'm ok with these results....

jimtreber
07-12-12, 03:18 AM
Jimtreber, it appear you have been using this product for about a week. Please let us know if your gains appear to be sustained after you've used it for a few weeks or months. It may be possible that your increase in MPG is actually due to you watching the monitor and unconsciously altering your driving style and not from this product. Then again, maybe it actually works and there is some bit of physics and thermochemistry I'm overlooking.

All right, I have a few months driving on the throttle body spacer. My thoughts and feelings about it are still the same. With all types of city driving (long warmups, short trips, easy driving, spirited driving, etc.) as I had done before, my worst mpg with the spacer is more than 2mpg better than my best I had gotten without the spacer before. Not trying to sell the idea, it just works for me. My highway driving is limited as is the mileage testing and the mpg doesn't seemed to have changed as dramtically if at all.
When i first installed it, I thought that I noticed a difference right away in running but wasn't positive. I now realize what that was. I recently installed the rest of the package (the cai) and notice the normal dead spots are back that had disappeared with the spacer alone. Suprisingly my mileage didn't further increase with the cai. It's possible that I'm driving differently now because of the sound of the cai. I was worried it would sound like the WAH sound of old 4 barrell carbs but instead has a great performance sound that doesn't start until 3000 rpm.