C-7 350 HP Best Replacement Air Filter

[EL_Carlson]

I have a Winnebago 2005 Journey36G with 8,500 miles that I am doing a major service do age not miles, want to replace the air filter. Is there an upgrade high flow replacement air filter? The Filters I have looked at are:
Racor P?N 114880-003
Farr AH 1197
Donaldson P537454
Parker 114880003
Wix 46748
I presently get about 7.7 miles / Gal would like to improve if possible, any suggestions would be help full.

Thank you for any help.

[Full.Monte]

That's a list of good filters. I have become a fan of Wix in the last couple years. I don't know if they are better than the others listed. I don't think there will be much difference in mileage between a new filter of one brand vs. a new filter of another brand. If you really want to increase your mileage, you might look elsewhere:

1. Stay out of the left lane and do 55 in the slow lane.
2. Make sure your tire pressures are in spec for the weight you are carrying.
3. Use a mpg gage like is contained in one of the OBDII gage clusters. It will train you how to drive to reduce fuel consumption.
4. Cut down on the weight of stuff in your RV by removing excess.
5. Realize that there is a limit to the mpg you will get. You are not likely to get what a Prius gets no matter what you do.

[MaverickBBD]

You might want to check out aFe (Advance Flow Engineering) air filters. Remember more air in is only half the equation. The other part is air(gas) out. You might want to up size your exhaust and replace that baffled muffler that Cat put on to slow the exhaust when they were still in the "on the road" race chasing exhaust emissions.

[doorguy]

Hello El_Carlson. Post #3 refers to the upgraded muffler being an Aero 5050XL. Thru his guidance and 1ciderdog's, I decided to go this route myself.
1ciderdog gave me all the part #'s, i.e., elbow, clamps, etc. The OEM muffler is 36" long and about 12" in diameter. The new one is 30" long and 7" dia. It really does make a difference in low end performance and increases hp and torque. If you install it yourself(it isn't that difficult) you can do it for about $250 in materials. If you have someone do it, one quote I had was $750 and they were marking up the muffler over 100%. Then you can decide if the AFE air filter is next. I haven't done the filter yet, because I replaced it in Jan with an OEM filter and it should last two years. Good luck, sir!

[lwasouth]

I would not recommend and after marker free breathing filter. They just let more dirt in your engine. Actually changing your OEM FILTER TOO OFTEN LETS MORE DIRT IN. The filter becomes more efficient at cleaning the air into your engine after a few hours of use. I agree with the exhaust 5050XL
with the resonator and if you want to go all the way the MP8 tuner at 15%. I did both of these and increased mileage from 7.1 original 16,000 miles to an average of 8.4 on a 15,000 mile trip

[lwasouth]

I would not recommend an after marker free breathing filter. They just let more dirt in your engine. Actually changing your OEM FILTER TOO OFTEN LETS MORE DIRT IN. The filter becomes more efficient at cleaning the air into your engine after a few hours of use. I agree with the exhaust 5050XL
with the resonator and if you want to go all the way the MP8 tuner at 15%. (half way on the dial) I did both of these and increased mileage from 7.1 original 16,000 miles to an average of 8.4 on a 15,000 mile trip

[rver98]

To be honest with you the MP-8 and Aero Muffler were the best mods I made to our MH. Low end torque and a quicker response from a start made a huge improvement. The AFE filter was the last upgrade and I have not really noticed much of a difference.

Good luck on your decision

[rvjimmy]

Go with the Aero muffler it doesn't pay to put more air in if it can't get out. Put a 5050XL on mine and it really did make a difference. It's a bit louder but it now sounds like a big boy instead of a puss boy.

[Poptop]

Does anyone know if installing the 5050XL and/or the MP8 changes the emissions? In Colorado we have to do an annual smog check. Thanks.

[sandcar361]

They didn't say anything to me here in Arizona last month when I went through emissions. Mine is an 2006 so that might have something to do with it.

[InfinityJim]

The only time you should change the air filter on a diesel is when the gauge tells you to. On tractor's (commercial trucks) they have the air restrictor gauge inside the cab so the driver can properly watch it. What is recommended on motorhomes is WHEN the gauge reaches your limit to reset the gauge and drive the coach to make sure it really is pulling that hard of vacuum and if it is indeed, then change the filter at that time. Over changing your air filter on a diesel will cause way more damage to your engine then overdriving with a dirty/plugged filter. It is correct that it takes a certain amount of dirt in a new filter until it starts preforming, and while it’s in that stage it’s unknown how much dirt passes thru and enters the engine. Some seminar’s I’ve been to form different engine manufactures will start out saying it takes a cup of dirt to dust a motor, whether it’s a cup today or a cup over 20 years.

I’ve seen too many motors dusted over the years, we only use factory replacement filters (normally ECO, Fleetguard, Donaldson, etc..) I don’t like any of the lifetime K&N type filters, how do you know you got enough oil on it after cleaning or too much? Most of the coaches we’ve seen with dusted motors are from a fitting between the engine and the filter coming apart and letting unfiltered air (DIRT) into the motor. BUT, some have been from the owner changing his air filter every year for the past 7-8 years or from putting in the K&N type and not cleaning / re-oiling correctly.

[rver98]

Originally Posted by InfinityJim

The only time you should change the air filter on a diesel is when the gauge tells you to. On tractor's (commercial trucks) they have the air restrictor gauge inside the cab so the driver can properly watch it. What is recommended on motorhomes is WHEN the gauge reaches your limit to reset the gauge and drive the coach to make sure it really is pulling that hard of vacuum and if it is indeed, then change the filter at that time. Over changing your air filter on a diesel will cause way more damage to your engine then overdriving with a dirty/plugged filter. It is correct that it takes a certain amount of dirt in a new filter until it starts preforming, and while it’s in that stage it’s unknown how much dirt passes thru and enters the engine. Some seminar’s I’ve been to form different engine manufactures will start out saying it takes a cup of dirt to dust a motor, whether it’s a cup today or a cup over 20 years.

I’ve seen too many motors dusted over the years, we only use factory replacement filters (normally ECO, Fleetguard, Donaldson, etc..) I don’t like any of the lifetime K&N type filters, how do you know you got enough oil on it after cleaning or too much? Most of the coaches we’ve seen with dusted motors are from a fitting between the engine and the filter coming apart and letting unfiltered air (DIRT) into the motor. BUT, some have been from the owner changing his air filter every year for the past 7-8 years or from putting in the K&N type and not cleaning / re-oiling correctly.

The AFE is a dry type filter. Soap and water only for cleaning and air dry. No oil applied.

[MKelley]

Would you all do the same upgrade mp-8 and aero muffler to a c-9? And if so what # areo muffler would you use?

[rver98]

Originally Posted by MKelley

Would you all do the same upgrade mp-8 and aero muffler to a c-9? And if so what # areo muffler would you use?

The Aero Muffler would be the same #5050XL (5" exhaust). Since you have a C9 CAT which already produces 1200lbs. of torque, the MP-8 will produce too much torque for the Allison MH3000. The muffler would be a good upgrade!

Good luck