This is a post I made about two years ago on another site. I did the Aero and a air filter up-grade!
The links below are from test done a few years ago at best! Might be never data out there. Good Luck!
More MPG’S .
I think we all want more MPG’s with the cost of fuel? Well I wanted to do this right because of all the great information that I have gotten here over the years by fellow rv’er who have done the home work to do things right. So here is what I did.
My M/H info. 2006 Newmar Mountain Aire 43’ 3 axle with an ISL 400 Cummins. I don’t baby it, if the speed limit is 75, I drive 75. I get between 6.6 to 6.8 mpg. I know that some people say they get 8+ with this size M/H but I don’t. I do have a heavy right foot!
(Added today 10-29, I have slowed down to 65)
First of all, I have read many post on the Aero Turbine muffler and I though what the heck, I’ll give it a try. I purchased the 5050xl for $145.00 delivered. Had to purchase two band clamps, one was 4” to 5” and the other was 5” to 5”. Total cost was $162.00 and I did the labor. Took me about three hours, pictures below.
But why stop there? I have also heard of people installing the AFE 70-5013 air filter which list for $345.00 but I found it for $285.00. But I decided to do a little more reading and checking things out and this is what I did and maybe you will want to follow.
I found a few studies of air filters on this forum, here are the links to them. These studies are very precise and are done in a real type environment that the filters would see every day in my opinion. What really concerned me the most was the lack of filtering a clean K and N style gauze filter did when clean. It allowed over seven times the particulate to pass over other filters. Kind of scary to me.
Remember to not always belive what you read?
Here's the info I have on air filter performance. Tests were done using
SAE J726C Test Method 5-best --> 1-worst
Oiled foam Paper Oil Bath Oiled
(AMSOIL, UNI) (K&N)
Large particle efficiency 5 5 5 4
Small particle efficiency 5 4 1 2
Airflow capacity 5 2 3 5
Dust holding capacity 4 2 5 2
Load up characteristic 4 1 5 1
Backfire characteristic 3 2 5 3
Cleanability 4 1 4 3
Well after reading the test results and knowing that I didn’t want to have to clean a AFE filter every three thousand miles and knowing that it does not filter that good I didn’t want to go with it. And a foam type filter would not be available because of the size, so I did this.
My Spartan book has the listing for my stock air filter, it is a Racor 62891-001. When I read about the filter I was surprised at the specs of the filter. A diesel mechanic that I know said many of the M/H’s do not have adequate air flow to the engine even with a new filter, let alone one that has a few miles on it.
Air Flow 820-1200 cfm
Height 24.0 in. (61.0 cm)
Diameter 9.8 in. (24.9 cm)
Outlet Size 6.0 in. (15.2 cm)
Inlet Size 6.0 in. (15.2 cm)
Weight 16.0 lbs (7.3 kg)
So I went to the Racor web site and found this filter that is the same style just 1 ¼ larger, Racor 62891-002
Air Flow 1100-1650 cfm
Height 24.0 in. (61.0 cm)
Diameter 11.0 in. (27.9 cm)
Outlet Size 7.0 in. (17.8 cm)
Inlet Size 7.0 in. (17.8 cm)
Weight 19.0 lbs (8.6 kg)
As you can see, the flow difference of the filters a lot. But one thing that I feel makes big difference too in the amount of particulate matter that the filters can hold before reaching the life expectancy of the filter. The larger filter can about one hundred grams more, giving it a longer life. Also, my stock filter cost me $117.00 plus $17.00 shipping while the larger filter is $97.00 and know shipping. It is a stock filter a Freightliner.
So I decided to go with the lager filter, I had to order a 90 degree angle from 6” to 7” and a straight 6” to 7” and I ordered the correct clamps to hold the filter, 2 @ 12.50 part #71921-002. Total cost for filter and parts, $185.00. I had to cut my air filter stand down 1”, take 1” off the down pipe that goes into the 90 and take 2” off the pipe from the filter to the turbo. I also cut the clamps in half to make it easier to change the filter. The way my M/H is set up, the coolant tank is very close to the air filter and I had to bend the clamps down to change the filter. Now I just unbolt the front of the clamps. It took me 4 hours to do the job. Here are a few pictures for you.
So what did I gain? Well I spent $330.00 so I was hoping to gain .5 mpg. I feel that would be a good investment in doing these two things, that’s about $0.20 per gallon savings and it will add up fast.
But this is what I got. First trip out and I averaged 7.8 mpg. That is a plus $0.40 per gallon savings and my M/H felt peppier and ran cooler. Well there ya go. Hope I helped you out. I might even go the larger 13 1/2 filter if I have the room, the spec on that are a huge jump in flow. Thanks