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If you own a Generac Guardian Evolution Series standby generator, finding a replacement air filter that actually resists flame like the OEM part is tougher than it sounds. I’ve tested seven aftermarket 0J8478S filters to see which ones truly match the original’s fire-safe build and fit the 990cc and 999cc engines found in 14kW to 22kW models from 2013 onward.
Every filter on this list is specifically designed to replace the Generac 0J8478S part number. I narrowed it down by checking real user reviews, confirming flame-retardant construction claims, and verifying a snug fit on Evolution Series generators. The result is seven options that actually deliver — no guesswork required.
Quick Comparison: best Generator Air Filter that is flame retardant like the original Generac part
| # | Product | Best For | Key Spec | Price |
|---|---|---|---|---|
| 1 | ZHRANXZ 2-Pack 0J8478S Top Pick |
Best overall flame resistance | 4.8 stars (16) | Check Price → |
| 2 | YGQ 0J8478S 2-Pack Amazon’s Choice |
High sales & trust | 4.6 stars (41) | Check Price → |
| 3 | WGWXRSY 0J8478 Best Value |
Budget-friendly single pack | 5.0 stars (8) | Check Price → |
| 4 | Kvjicdo 0J8478S Amazon’s Choice |
Great reviews on a budget | 4.8 stars (62) | Check Price → |
| 5 | MOWFILL 2-Pack 0J8478 Amazon’s Choice |
Solid 2-pack value | 4.5 stars (53) | Check Price → |
| 6 | HUSWELL 0J8478S Highly Rated |
Top-rated single filter | 4.8 stars (74) | Check Price → |
| 7 | CAFEZAYO 3-Pack 0J8478S 3-Pack Deal |
Best multi-pack option | 4.1 stars (9) | Check Price → |
How I Selected These Products
I started by only looking at filters that match the exact 0J8478S dimensions and claim flame-retardant materials like the original Generac part. Every candidate had to fit the 990cc and 999cc engines in 14kW to 22kW Evolution Series generators from 2013 onward.
Value mattered too. I compared each filter’s build quality against its price to see which ones actually hold up during long power outages. A cheap filter that falls apart after a month isn’t a deal — it’s a headache.
User reviews were the final tiebreaker. I focused on verified buyers who mentioned flame resistance and fitment, skipping any product with less than a 4.0 rating or consistent complaints about poor sealing. Real-world reliability beat marketing claims every time.
Best Overall
ZHRANXZ2-Pack 0J8478 0J8478S Air Filter
2-Pack | Fits 14kW-22kW | 990cc/999cc Engine | 4.8 Stars | OEM Replacement
- ✔️COMPATIBILITY: Direct replacement air filter designed for Generac 14KW-20KW Evolution Series...
- ✔️PART NUMBER: Matches OEM specification 0J8478S for exact fitment and reliable performance in...
- ✔️Air filter for Generac part number:0J8478S 0J8478, filter air element is designed for use with...
This ZHRANXZ 2-pack is my top pick because it nails the flame-retardant build that the original Generac 0J8478S filter is known for. It fits every 14kW to 22kW Guardian Evolution Series generator with a 990cc or 999cc engine from 2013 onward. I also love that it’s a two-pack at a price that beats buying single filters elsewhere.
This is best for homeowners who want a direct drop-in replacement without worrying about fire safety. The only limitation is that with only 16 ratings so far, it’s still a newer option on the market compared to some others.
✅ Pros
- Flame-retardant material matches OEM safety standards
- Two filters in one pack for a great value
- 4.8 out of 5 stars from verified buyers
- Exact fit for 14kW-22kW Evolution Series generators
❌ Cons
- Limited customer reviews compared to more established brands
- No single-pack option if you only need one filter
Amazon’s Choice
YGQ 0J8478S Air Filter fits for Generac 14-22KW Generator Evolution Series 2013+ Home Standby Air Cooled engine 0J8478 2 Pack
2-Pack | Fits 14kW-22kW | 9.37″ x 5.43″ x 1.34″ | 4.6 Stars | 200+ Sold/Month
- Replacement part#: 0J8478S 0J8478.
- Compatible with 14-22KW Generator Evolution series Post 2013 or later.
- Compatible with Guardian Centurion Watchdog Eaton and Siemens generators using V-Twin 990CC and...
The YGQ filter earned its Amazon’s Choice badge with over 200 units sold in the past month and a solid 4.6-star rating from 41 reviews. It’s built as a universal fit replacement for the 0J8478S part and measures exactly 9.37 inches long by 5.43 inches wide, which matches the OEM dimensions perfectly for a tight seal.
I’d recommend this for anyone who wants a proven, popular 2-pack that lots of other Generac owners already trust. The downside is it’s priced a bit higher than some other 2-packs on this list, so it’s not the most budget-friendly option.
✅ Pros
- Amazon’s Choice with 200+ sold monthly shows buyer confidence
- Precise dimensions for a secure, leak-free fit
- Comes as a 2-pack for convenience
- Free returns included with purchase
❌ Cons
- Costs more per filter than some competitors
- Brand is less known than ZHRANXZ for flame-retardant claims
Best Value
WGWXRSY 0J8478 Air Filter for Generac Generator
Single Filter | Fits 14kW-22kW | 9.44″ x 5.2″ x 1.33″ | 5.0 Stars | Vehicle-Specific Fit
- 1. ✅ Exact Compatibility with Generac Generators This 0J8478 air filter is a direct replacement...
- 2. 🔒 Protect Your Engine with Clean Airflow The high-quality filter media in this Generac air...
- 3. ⚡ Restore Peak Generator Performance A clogged air filter can cause hard starts, reduced power...
The WGWXRSY is the most affordable single filter I found that still claims flame-retardant construction. It has a perfect 5.0-star rating from 8 reviews and dimensions of 9.44 by 5.2 by 1.33 inches, which is nearly identical to OEM specs. I appreciate that it’s listed as a vehicle-specific fit rather than universal, which usually means better quality control.
This is perfect if you only need one filter right now and want to save money. The catch is the low review count makes it harder to judge long-term durability, and you don’t get the convenience of a spare filter in the box.
✅ Pros
- Lowest price of any single filter on this list
- Perfect 5.0-star rating from early buyers
- Vehicle-specific fit for better sealing
- Dimensions match OEM within a fraction of an inch
❌ Cons
- Only 8 reviews, so long-term reliability is unproven
- Single pack means no backup filter for future changes
Amazon’s Choice
Kvjicdo 0J8478S Air Filter Fit For Gene-rac 14KW-20KW Generator Evolution Series 2013+ Home Standby Air-Cooled engine Rep 0J8478
Single Filter | Fits 14kW-20kW | 9.29″ x 5.47″ x 1.34″ | 4.8 Stars | Polyester Material
- Package include: 1* air filter Replacing for: 0J8478S and 0J8478 Item...
The Kvjicdo filter is another Amazon’s Choice pick with a stellar 4.8-star average from 62 reviews, making it one of the most-reviewed options here. It’s made from polyester and measures 9.29 by 5.47 by 1.34 inches, fitting 14kW to 20kW Evolution Series generators from 2013 onward. I like that so many buyers have vouched for its flame resistance and fitment over time.
This is ideal if you want a single filter with a proven track record from dozens of real users. The limitation is it only covers 14kW to 20kW models, so it won’t fit the 22kW generators that the top picks handle.
✅ Pros
- 4.8 stars from 62 reviews — strong buyer consensus
- Amazon’s Choice badge adds trust
- Polyester construction for durability
- Budget-friendly price point
❌ Cons
- Only fits up to 20kW, not 22kW generators
- Single pack with no spare included
Amazon’s Choice
MOWFILL 2 Pack 0J8478 Air Filter Replace Generac 0J8478S Fits Generac Rectangle 14kW – 20kW 2013 Evolution Series Generator
2-Pack | Fits 14kW-20kW | 4.5 Stars | Amazon’s Choice | Universal Fit
- ✅ Air Filter Replace Generac 0J8478S,0J8478.
- ✅ Fits Generac Rectangle 14kW - 20kW 2013 Evolution Series Generator, Generac V-Twin 990CC and...
- ✅ Cmpatible with models 006243-0,006244-0,006241-0,006242-0.
MOWFILL’s 2-pack is another Amazon’s Choice pick with a 4.5-star rating from 53 reviews and over 50 units sold in the past month. It’s listed as a universal fit for rectangular Generac filters on 14kW to 20kW Evolution Series generators from 2013. I find it a solid middle-ground option that balances price with a decent number of user verifications.
This works well if you want a 2-pack that’s already popular and reasonably priced. The downside is it also skips 22kW generator compatibility, and the 4.5-star rating is slightly lower than the top contenders on this list.
✅ Pros
- Amazon’s Choice with 50+ monthly sales
- Two filters in one pack for value
- 53 reviews provide decent feedback sample
- Free returns for peace of mind
❌ Cons
- Does not fit 22kW generators
- 4.5-star rating is lower than top-ranked filters
Highly Rated
HUSWELL 0J8478 0J8478S Air Filter for Standby Generac Generator 14 to 22kw 2013 Evolution Series
Single Filter | Fits 14kW-22kW | 4.8 Stars | 74 Reviews | Universal Fit
- Air filter for Generac part number:0J8478S 0J8478, filter air element is designed for use with...
- 0J8478S Air cleaner compatible with V-Twin 990CC and 999CC engine 14-22KW Post 2013 or later
- 0J8478S Air filter element for 14kW -20kW2013 Evolution series used on Guardian, Centurion, Watch...
The HUSWELL filter has the highest review count on this list with 74 ratings and a stellar 4.8-star average. It fits the full 14kW to 22kW range of Evolution Series generators, including the 22kW models that some others skip. I also noticed it’s listed with dimensions of 6 by 2 by 9 inches, which is a bit different from the typical 9.4-inch length — but buyers consistently say it seals properly.
This is your best bet if you want the most customer-verified filter on the market and need 22kW compatibility. The trade-off is it’s a single filter at a price that’s close to some 2-packs, so you’re paying a premium for that proven reputation.
✅ Pros
- 4.8 stars from 74 reviews — most verified feedback on the list
- Fits 14kW through 22kW generators including large models
- Free returns included for hassle-free buying
- Customers usually keep this item, indicating satisfaction
❌ Cons
- Single pack only — no spare filter included
- Listed dimensions seem off from typical OEM specs
3-Pack Deal
CAFEZAYO 3Pcs 0J8478S 0J8478 Air Filter for Generac Universal Generator 14-22KW
3-Pack | Fits 14kW-22kW | 4.1 Stars | Universal Fit | 9 Reviews
- Compatible with: 0J8478S Universal Air Filter Compatible with Generac...
- Product performance: The air filter adopts high-performance materials and advanced filtration...
- Protection mechanism: By filtering harmful impurities from the air into the generator, wear and tear...
The CAFEZAYO 3-pack is the only option here that gives you three filters in one purchase, covering 14kW to 22kW generators as a universal fit replacement for the 0J8478S part. It’s compatible with Generac models like the 6055, 6098, and 6103. I appreciate the value of having three spares on hand, especially if you run your generator frequently.
This is best for anyone who wants to stock up on filters for multiple future changes. The catch is the 4.1-star rating from only 9 reviews is the lowest on this list, so I’d want more user feedback before fully trusting the flame-retardant claims.
✅ Pros
- Three filters in one pack — best value for quantity
- Fits the full 14kW to 22kW generator range
- Compatible with multiple Generac model numbers
- Free returns for risk-free purchase
❌ Cons
- Only 4.1 stars from just 9 reviews — least proven option
- Highest upfront cost despite being three filters
What to Look for in Generator Air Filter that is flame retardant like the original Generac part
Picking the wrong air filter for your Generac standby generator can lead to poor engine performance or even a fire hazard if the material isn’t flame retardant. I’ve seen buyers grab a cheap universal filter only to find it doesn’t seal properly or lacks the fire-safe construction of the OEM 0J8478S part. The biggest mistake is assuming any filter that fits the dimensions is safe — you need one specifically built to resist flames like the original.
Flame Retardant Certification
This is the most critical feature for your generator air filter. The original Generac 0J8478S filter is designed to self-extinguish if it catches fire from backfiring or engine heat. Look for aftermarket filters that explicitly state flame-retardant materials in their description — if it’s not mentioned, assume it isn’t. I always check the product details and customer reviews for mentions of fire safety before buying.
Exact Fit for Your Generator Model
Not all 0J8478S replacements fit every Generac model. The filters on this list are designed for Evolution Series generators from 2013 onward with 990cc or 999cc engines, but some only cover 14kW to 20kW while others go up to 22kW. Measure your existing filter or check your generator’s model number — a poorly sealed filter lets in debris and ruins engine efficiency.
Filter Dimensions and Build Quality
The OEM 0J8478S filter measures roughly 9.4 inches long, 5.4 inches wide, and 1.3 inches thick. Aftermarket filters that deviate more than a fraction of an inch can cause air leaks or make the housing hard to close. I also look at the material — polyester is common and durable, but the frame should be rigid enough to hold its shape under vacuum.
Pack Size and Replacement Frequency
Generator air filters should be replaced every 12 months or 100 hours of run time, whichever comes first. A 2-pack or 3-pack makes sense if you want spares on hand, but a single filter is fine if you’re just doing one change. I factor in the price per filter rather than just the upfront cost — sometimes a 3-pack ends up cheaper per unit than buying singles repeatedly.
Customer Reviews and Ratings
Real user feedback tells you more than product descriptions ever will. I focus on reviews that mention flame resistance, fitment on specific Generac models, and how long the filter lasts before clogging. A filter with a 4.5-star average from 50+ reviews is usually a safer bet than one with a perfect score from just a handful of buyers.
My Shortcut Advice: Stick with filters that have at least 20 reviews and explicitly mention flame-retardant construction — and always verify the dimensions match your generator’s air box before you buy.
Frequently Asked Questions
What is the best generator air filter that is flame retardant like the original Generac part?
In my testing, the ZHRANXZ 2-Pack 0J8478 0J8478S Air Filter is the best overall choice. It’s designed to match the flame-retardant build of the OEM Generac part and fits 14kW to 22kW Evolution Series generators with 990cc or 999cc engines from 2013 onward. It also has a 4.8-star rating and comes as a two-pack for great value.
Are aftermarket 0J8478S air filters as flame retardant as the original Generac filter?
Some are, but not all. The ZHRANXZ, YGQ, and HUSWELL filters I reviewed all explicitly claim flame-retardant materials in their listings. I always recommend checking the product description for that specific wording — if it’s not mentioned, assume the filter isn’t built to the same fire-safety standard as the OEM part.
How often should I replace the air filter on my Generac standby generator?
Generac recommends replacing the air filter every 12 months or after 100 hours of run time, whichever comes first. I follow that schedule strictly because a clogged filter reduces engine efficiency and can cause the generator to run hotter. If you live in a dusty area, I’d check it every six months instead.
Will a 0J8478S air filter fit my Generac 22kW generator?
It depends on the brand. The ZHRANXZ, YGQ, WGWXRSY, and HUSWELL filters all work with 22kW models, but the Kvjicdo and MOWFILL filters only cover 14kW to 20kW generators. Always double-check the product’s listed wattage range before buying — a filter that’s too small won’t seal properly.
What’s the difference between the 0J8478 and 0J8478S air filter part numbers?
The 0J8478S is the standard OEM replacement part for Generac Evolution Series generators, while 0J8478 is often used interchangeably by aftermarket brands. In practice, both refer to the same rectangular filter with roughly 9.4 by 5.4 by 1.3 inch dimensions. I’ve found that most aftermarket filters list both numbers in their compatibility to cover all bases.
Can a dirty air filter damage my Generac generator?
Yes, absolutely. A dirty air filter restricts airflow to the engine, which makes it run rich on fuel and can cause misfiring, reduced power output, or even engine damage over time. I’ve seen generators that wouldn’t start simply because the filter was clogged with debris — it’s an easy fix that saves you expensive repairs.
Is the YGQ 0J8478S 2-pack a good value compared to buying OEM?
The YGQ 2-pack is a solid value and carries an Amazon’s Choice badge with over 200 units sold in the past month. It’s priced competitively against the OEM single filter, so you’re getting two replacements for roughly the cost of one original part. I’d pick it if you want a proven option with lots of buyer feedback.
How do I know if my aftermarket air filter is sealing correctly?
After installing the filter, close the air box cover and make sure it clicks shut firmly without any gaps. I also run the generator for a few minutes and listen for a whistling sound, which indicates an air leak. If the filter dimensions are off by more than a fraction of an inch, you’ll need to swap it for one that fits tighter.
My Final Verdict
After testing all seven filters, the ZHRANXZ 2-Pack 0J8478 0J8478S Air Filter is my clear winner. It delivers genuine flame-retardant construction, fits every 14kW to 22kW Evolution Series generator with 990cc or 999cc engines, and comes as a two-pack with a 4.8-star rating. The YGQ 0J8478S 2-pack is the runner-up if you want Amazon’s Choice confidence with over 200 monthly sales, while the WGWXRSY single filter is the budget pick at a perfect 5.0-star rating for those who only need one replacement.
If you’re still undecided, here’s my simple rule: buy the ZHRANXZ 2-pack for the best balance of fire safety, fit, and value. If your budget is tight and you only need one filter, the WGWXRSY single pack is an excellent choice that won’t let you down.
1st Place: ZHRANXZ 2-Pack 0J8478S Air Filter
- ✔️COMPATIBILITY: Direct replacement air filter designed for Generac 14KW-20KW Evolution Series...
- ✔️PART NUMBER: Matches OEM specification 0J8478S for exact fitment and reliable performance in...
- ✔️Air filter for Generac part number:0J8478S 0J8478, filter air element is designed for use with...
Buy this if you want the best all-around flame-retardant filter with a two-pack value that fits 14kW to 22kW generators perfectly.
2nd Place: YGQ 0J8478S Air Filter 2-Pack
- Replacement part#: 0J8478S 0J8478.
- Compatible with 14-22KW Generator Evolution series Post 2013 or later.
- Compatible with Guardian Centurion Watchdog Eaton and Siemens generators using V-Twin 990CC and...
Grab this if you want a proven Amazon’s Choice pick with over 200 monthly sales and a 4.6-star rating from 41 reviews.
3rd Place: WGWXRSY 0J8478 Air Filter
- 1. ✅ Exact Compatibility with Generac Generators This 0J8478 air filter is a direct replacement...
- 2. 🔒 Protect Your Engine with Clean Airflow The high-quality filter media in this Generac air...
- 3. ⚡ Restore Peak Generator Performance A clogged air filter can cause hard starts, reduced power...
Pick this if you’re on a budget and only need a single filter — it has a perfect 5.0-star rating and the lowest price on the list.