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farmingdad's avatar
farmingdad
Explorer
Dec 17, 2017

Air filter

My isl 425 in my Newmar is not getting enough air, the air gauge back nx to engine almost closes up after driving 100 miles with a new air filter in it an I'm just getting 6.2 mpg I'm thinking about drilling holes in the metal canister to give her some more air an might get better fuel mileage what do you think , I seen a guy with a Monaco that put a Finn custom made up on side corner of coach to put more air in filter , he said he got 2 more mpg ..
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  • DSDP_Don's avatar
    DSDP_Don
    Explorer
    Dec 17, 2017
    What you're calling the "air gauge", is actually a filter gauge and they are absolutely useless. You don't say what speeds you're driving, but 6.2 mpg in a Mountain Aire DP is not far off from what most get. Mid 7's would be close to normal if you're keeping the speed under 65.

    You're asking for issues if you drill the air filter canister. Your current design picks up cool air from the roof line of the coach. It also filters out water through a flapper when rain water is ingested. If you drill the air filter, you'll be picking up hot air form the engine and possibly water when driving in the rain.....basically a bad idea!

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