# Tow Vehicle Mods: Power And Mpg Gains



## 2422 (Jul 20, 2006)

I pull a 25' Keystone Outback Kargaroo, normally with my 800 lb motorcycle in the storage bay with a 4.8L 1999 Chevy Silverado. It has done a good job but seemed to struggle a bit on bigger hills so I started investigating what I could do to increase power without breaking the bank, and have come to an amazing discovery! For less then $2,000 I've basically got an entirely new truck - I've gone from getting 14-15 MPG in town to EIGHTEEN (18) and can get as much as 20 on the highway (no tow at those numbers of course) and have seen corosponding increases of 2-3 MPG when towing (I'm now getting 11 MPG average instead of 9) and have experienced much better torque and horsepower. What did I do to acheive this miracle? Simple - I pulled some performance mods typical to 'hopping up' my engine as follows:

"Cold Air" Intake kit with High-flow MAS sensor replacement ($400)
Hypertech power programmer ($250)
80mm Throttle body and spacer upgrade ($250)
High flow cat-back (from catelitic convertor on) exhaust ($200)

The truck outperforms most 5.3L engine rigs now, and except for being a little bit louder then stock and getting better gas mileage has not changed much at all. The biggest change IMO was the power programmer, but the throttle body and exhaust made a LOT of difference with the torque, which helped pulling a lot.

I'd be interested in knowing what MPG most people are getting pulled 7-8 K trailers with similar rigs (mid-sized v8's like my 305 / 4.8L chevy) and whether they have made changes to increase power and performance and if so what they felt was worth the money? My next steps are going to be towards aerodynamics and it LOOKS like I may get another MPG (maybe two if I'm LUCKY) from those changes ... what has been your experiences?


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## Ghosty (Jan 17, 2005)

I have done basically what you have done but did it to my 5.3L and also saw increases in power and mpg..

I did a "Cold Air" Intake kit ($120)
80mm Throttle body and spacer upgrade ($100)
High flow cat-back (from catelitic convertor on) exhaust ($210)

Be interested on hearing more on the Hypertech power programmer ($250) ...

But with what I have done I went from 285 HP to 315 HP on one of those dynometer thingys and increased my torque quite a bit...

My mpg is 19.3 on the hiway (no towing) and 12.3 towing a 23RS...


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## Scrib (Jun 28, 2005)

With a 5.4L Expedition, I'm at 17-and-change solo and 11-and-change towing (both highway, but not freeway), with a K&N cold air intake and a Superchips programmer. I'm planning on a better exhaust system this summer. Before the mods, it was 14 and 9.


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## Ldeneau (Mar 8, 2007)

I just ordered a performance kit today for my 2004 Seirra 2500HD 6.0L from:
http://www.rpmoutlet.com/newgmcsuv.htm

It has a AEM (dry-flow) "Cold Air" Intake kit,
DiabloSport power programmer flash tuner,
and Helix throttle spacer,
The kit cost $549.95
It supposed to add 43 more HP. I'll let you know.


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## NAturedog2 (Jan 29, 2007)

I have a 2005 chevy suburban and wondered how hard these things are to install? Is it something I can do myself? and how much more noise is it adding.


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## camping canuks (Jan 18, 2007)

NAturedog2 said:


> I have a 2005 chevy suburban and wondered how hard these things are to install? Is it something I can do myself? and how much more noise is it adding.


I had a K&N 770 Intake system put in , I suppose you could do it yourself however my truck is still under extended warranty so wanted to be cautious. But really you can do it yourself, the majority of the work is in stripping down the OME and then replacing. You get more a throaty growl when you accelerate but I would not say it is excessive at all. The manfuacture indicates maxium hp at 14 at 3500 5000 rpm, I have not had it dyno'd yet


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## LordMuut (Jul 30, 2006)

06 Ram 2500 4x4 Hemi
Volant C.A.I.
Aeroturbine exhaust
Superchip flashpaq
I gained about 3mpg but it now runs like a 1/2 ton







. The Superchip made the biggest difference by far.


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## Pakeboy2 (Aug 13, 2005)

Installed a throttle body spacer, K&N air filter and dual out MagnaFlow muffler...maybe a 1 or 2 mpg improvement...and it sure sounds nice!


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## Rubrhammer (Nov 27, 2006)

What grade of fuel do you run when you tow? The tune on my ecm really helpedwith the higher octane gas. I still only run 89 as I just can't swallow the cost of premium. There has been alot of debate on performance trucks forum as to there being any benefit from the spacers. I think you've done a good job of integrating improvements to the breathing on the intake and exhaust. One without the other you won't realize the potential of any modification. One thing hat would probably give you a big boost it tq would be long tube headers. don't waste your moneyon the shorties. 
I'm getting 20.5 local and 21.3 on the freeways.Towoing 5700# 10.5 to 11.3. See truck in sig. 3.73s going in next week. Electric fans after easter.
Bob


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## TNOutbacker (Apr 23, 2005)

Does anyone have an opinion or experience using a single in dual out muffler set up. Is there anything to be gained other than "Hey that looks cool" and stereo exhaust or is it just extra money with no performance improvements?


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## Collinsfam_WY (Nov 9, 2006)

Unfortunately with my older 2v 5.4l Ford mod motor, I have read a report of adding aftermarket add-ons that affected towing performance little or none at all. Beware of the "AF1" cold air intake. I read one thread where 75% of the respondents took it off due to the drone it causes during towing (air noise). I am a bit nervous about "chipping" a motor and would rather stick to the basic formula of increasing airflow in + increasing airflow out. One day we can hopefully afford a 3/4 ton diesel. I don't want to drop alot of money into this 1/2 ton trying to get it to perform like a 3/4 diesel when I could save that money towards a new truck.

With the older 2v modular Fords, apparently aftermarket exhausts tend to drop tq while increasing hp. I understand that the Magnaflow setup does not cause this but it is big bucks ($450?). Sure, it would be nice if at some point, I could find a good (+hp/+tq/quiet) cold air intake setup and drop it in along with a larger throttle body then put on the Magnaflow setup.

-CC


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## GoVols (Oct 7, 2005)

If these aftermarket chips gain so much HP and MPG, I guess I don't understand why the manufacturers don't just tune the vehicles this way? The Big 3 are always in a horsepower war, and they also have to meet corporate fuel mileage targets. If the chips do both, why don't the manufacturers do it on the front end?


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## SoCalOutback (Dec 18, 2005)

GoVols said:


> If these aftermarket chips gain so much HP and MPG, I guess I don't understand why the manufacturers don't just tune the vehicles this way? The Big 3 are always in a horsepower war, and they also have to meet corporate fuel mileage targets. If the chips do both, why don't the manufacturers do it on the front end?


The after market programmer or chips do not gain HP and MPG with out the other mods. With the programmer alone you get one or the other and in most cases you get no MPG gain.

On my 4.6L F150 I added electric fans, cat back exhaust, AF1 intake, transmission cooler, and a programmer. The results impressed me until the transmission and rear end needed to be replaced at 100,000 miles. In the end I wish I would have saved my money for a bigger truck.

I ended up with replacing the entire truck with an F250.


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## hath27 (Feb 15, 2007)

I recently added a MAC cold air intake kit to my 5.4 3V ford, and I was impressed. I have picked up an honest 1mpg gain in daily driving. Going from 14mpg to 15mpg is a huge jump in my opinion, an well worth the $$ spent. (BTW, I got a smokin' deal on the kit from RMCR in Colorado Springs if anyone is interested)
I havent towed enough w/ it to get a mpg report w/ the trailer, but there is a noticable increase in power, although it is small.
The downside to CAI kit at least w/ the Ford, is that you do get a noticable increase in sound from the intake under load. It sounds pretty cool (like the old 4-barrel Holley days!!) but it can get a bit annoying when towing the trailer.
Last night I added a Gibson cat-back exhaust, and the Edge programmer should be here today. Now, the truck should run pretty good!
Will it ever be like a Diesel? NO WAY!! I owned 2 Psd's before this truck, and I towed a 10,000lb race trailer all over, those trucks will pull. Unfortunatly, they are big, expensive to repair, and here in CO, diesel is at least .25 more a gallon than unleaded. So a smaller gas truck is better for me for right now.
The reason the big 3 dont make their trucks run like we want them to is because it does decrease longevity of the truck as SoCalOutback says. Also increased in-cab sound (in my case for sure), along w/ cost are factors. So, you have to decide; is it worth it to you to increase the performance of your truck? Will you own it long enough to see the decreased life? Do you drive it enough to warrant the extra costs of upgrades?


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## Collinsfam_WY (Nov 9, 2006)

SoCalOutback said:


> If these aftermarket chips gain so much HP and MPG, I guess I don't understand why the manufacturers don't just tune the vehicles this way? The Big 3 are always in a horsepower war, and they also have to meet corporate fuel mileage targets. If the chips do both, why don't the manufacturers do it on the front end?


The after market programmer or chips do not gain HP and MPG with out the other mods. With the programmer alone you get one or the other and in most cases you get no MPG gain.

On my 4.6L F150 I added electric fans, cat back exhaust, AF1 intake, transmission cooler, and a programmer. The results impressed me until the transmission and rear end needed to be replaced at 100,000 miles. In the end I wish I would have saved my money for a bigger truck.

I ended up with replacing the entire truck with an F250.
[/quote]

That is solid information that goes along with my thoughts exactly...my truck is at 76k already. Adding performance mods like that will just get me into that same place you were at, looking at replacing the trans and/or rear end, more quickly than I can afford. I need my truck to last until about 110-115k when we can start looking at doing what you did (get a 3/4 ton). $ to get the mods. $ to repair. All of which can be put towards a new TV.

-CC


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## map guy (Jan 11, 2007)

collinsfam_tx said:


> If these aftermarket chips gain so much HP and MPG, I guess I don't understand why the manufacturers don't just tune the vehicles this way? The Big 3 are always in a horsepower war, and they also have to meet corporate fuel mileage targets. If the chips do both, why don't the manufacturers do it on the front end?


The after market programmer or chips do not gain HP and MPG with out the other mods. With the programmer alone you get one or the other and in most cases you get no MPG gain.

On my 4.6L F150 I added electric fans, cat back exhaust, AF1 intake, transmission cooler, and a programmer. The results impressed me until the transmission and rear end needed to be replaced at 100,000 miles. In the end I wish I would have saved my money for a bigger truck.

I ended up with replacing the entire truck with an F250.
[/quote]

That is solid information that goes along with my thoughts exactly...my truck is at 76k already. Adding performance mods like that will just get me into that same place you were at, looking at replacing the trans and/or rear end, more quickly than I can afford. I need my truck to last until about 110-115k when we can start looking at doing what you did. $ to get the mods. $ to repair. All of which can be put towards a new TV.

-CC
[/quote]

Pretty much why I decided on a 3/4 to truck instead of a 1/2 ton. After moding the suspension and powertrain for more capacity/power/torque you lower overall life -if you get rid of vehicles every 2-3 years this might work out .. I normally keep my vehicles till the wheels drop off









Map Guy


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## PDX_Doug (Nov 16, 2004)

Anything that can improve performance on my TV is good in my book. Especially fuel mileage these days.
But here is my question...

I don't do tune-ups and such on my vehicles anymore (who can these days?!). If I take my truck into the dealer for service with all this aftermarket equipment, are they going to know what to do with it? For that matter, will they even work on it? Or, are you now at the mercy of specialty shops (which probably do a better job anyway, but $$$).

Also, mention was made of needing to upgrade to premium fuel. From a pure performance perspective, that's fine, but when it comes to MPG the higher fuel costs could easily offset the savings you get from an extra 1-2 MPG.

Any thoughts from those of you that have done these mods?

Happy Trails,
Doug


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## Collinsfam_WY (Nov 9, 2006)

Doug - FYI - the "tuners" will custom program your PCM based upon fuel octane. The gal I talked to recently at a respected performance shop indicated to me that the gains obtained from tune program based upon regular 87octane fuel are quite small in comparison to those gained from the 91-92 octane based tunes. She repeatedly tried to push the tunes based upon usage of high octane fuel. I didn't like that at all because you get a load of bad fuel (I have) and you are in trouble. I mentioned this to her and she started going on about "brand name" fuel. I told her my bad load was supposedly 90 octane from a Diamond Shamrock that I had put into my '71 Cuda which I had built the 340's compression to require 90 or above (10.5:1). She started questioning Diamond Shamrock and whether it was a legit brand or not "I've never even heard of that". This conversation made me very leery of using a custom tune program when I consider the location I may be camping and where I may have to get fuel at in that area.


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## map guy (Jan 11, 2007)

PDX_Doug said:


> Anything that can improve performance on my TV is good in my book. Especially fuel mileage these days.
> But here is my question...
> 
> I don't do tune-ups and such on my vehicles anymore (who can these days?!). If I take my truck into the dealer for service with all this aftermarket equipment, are they going to know what to do with it? For that matter, will they even work on it? Or, are you now at the mercy of specialty shops (which probably do a better job anyway, but $$$).
> ...


On the dealership issue it is going to be a one on one kind of answer. Also, will depend on if a warranty is involved... The big three actively deny warranty coverage -if knowledge of certain power adders are referenced on the work orders and if the PCM/ECM data tables are found modified to non-factory parameters .... Not sure for Nissan though.... This issue is always a regular topic on the Diesel brand specific forums.

Map Guy


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## SoCalOutback (Dec 18, 2005)

PDX_Doug said:


> Anything that can improve performance on my TV is good in my book. Especially fuel mileage these days.
> But here is my question...
> 
> I don't do tune-ups and such on my vehicles anymore (who can these days?!). If I take my truck into the dealer for service with all this aftermarket equipment, are they going to know what to do with it? For that matter, will they even work on it? Or, are you now at the mercy of specialty shops (which probably do a better job anyway, but $$$).
> ...


The biggest difference I found is when I took my engine driven fan off and put electric fans on. From the research I did this adds up to 15 HP. The next thing I did was add the magna flow cat back exhaust. This improved my MPG about 1 MPG. Then I added the cool air intake and did not notice any better fuel economy but a bit more power. All of the above mods can be done without running premium fuel.

I then purchased a SuperChips programmer. I had it configured with four modes. Stock, 89 octane towing, 91 octane towing, 91 octane performance. The programmer worked great but the added stress on the trans and rear end was to much for my truck.

If I was stuck with a 1/2 ton truck with to little power I would do all the above except the programmer. I don't think you will make the money back on MPG savings but you will get better towing performance.

Here is where I purchased all my upgrades.


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## Rubrhammer (Nov 27, 2006)

collinsfam_tx said:


> Doug - FYI - the "tuners" will custom program your PCM based upon fuel octane. The gal I talked to recently at a respected performance shop indicated to me that the gains obtained from tune program based upon regular 87octane fuel are quite small in comparison to those gained from the 91-92 octane based tunes. She repeatedly tried to push the tunes based upon usage of high octane fuel. I didn't like that at all because you get a load of bad fuel (I have) and you are in trouble. I mentioned this to her and she started going on about "brand name" fuel. I told her my bad load was supposedly 90 octane from a Diamond Shamrock that I had put into my '71 Cuda which I had built the 340's compression to require 90 or above (10.5:1). She started questioning Diamond Shamrock and whether it was a legit brand or not "I've never even heard of that". This conversation made me very leery of using a custom tune program when I consider the location I may be camping and where I may have to get fuel at in that area.


I have an ecm that I had reprogramed and this is what I learned from my research leading up to that purchace.Even stock ecms will allow better performance on premium fuel because with all the sensors the modern engines have the computer will feed in as much spark advance as the fuel being used will allow up to the limits of the program in the ecm and adjust fuel delivery accordingly. The tuners, whether hand held or like I had done, expand the advance curve and fuel mapping to allow more power. I like mine because I don't have to use different "settings",just put in the fuel I want and derive as much benefit as it will give me. I agree that the mileage increase may not offset the price difference of the higher octane but the driveability is worth it.
I just had the ecm reprogrammed for my gear change and new tire diameter and had the pin turned on so I can put in my LS1 fans. 
It'll never be a Duramax but it is paid for and does the job.LOL
Bob
Hot rodders never die, they just find new projects.


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## map guy (Jan 11, 2007)

Rubrhammer said:


> Hot rodders never die, they just find new projects.


A profound statement. If you are a GM hot rodder and are interested in tuning software -give EFI Live a look...EFI Live

Map Guy


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## Ldeneau (Mar 8, 2007)

NAturedog2 said:


> I have a 2005 chevy suburban and wondered how hard these things are to install? Is it something I can do myself? and how much more noise is it adding.


I put the kit I bought in yesterday. I'm no mechanic but it went pretty smoothly.
Taking my time it took about 4.5 hours. I will be taking a 200 mile trip in a couple
of weeks so I'll see how much it helps.


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