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If you’re maintaining an Onan diesel generator, you’ve probably noticed two different WIX air filter part numbers floating around. The WIX 49697 is a cube-like filter (7.36″ x 5.3″ x 5.35″) designed for the Quiet 7500 Diesel, while the WIX 49087 is a tall, skinny panel filter (2″ x 2″ x 12.9″) built for other Onan generator models.
I wrote this guide for anyone who’s staring at their generator’s air box and wondering which of these two WIX filters actually belongs inside it. Picking the wrong one means a loose seal or a filter that simply won’t fit, so let me save you the headache.
🏆 Quick Picks — My Top Recommendations
Best Overall: WIX 49697
Perfect fit for the Onan Quiet 7500 Diesel with a near-perfect 4.9-star rating from 59 reviews — Check Price →
Runner-Up: WIX 49087
Tall, slim 12.9″ panel filter for other Onan generators, backed by 411 ratings at 4.8 stars — Check Price →
Let me put the key specs side by side so you can see exactly how these two WIX filters stack up against each other.
Full Specs Comparison
| Specification | WIX 49697 Engine Air Filt | WIX 49087 Engine Air Filt |
|---|---|---|
| Product Dimensions | ✅ 7.36″L x 5.3″W x 5.35″H | 2″L x 2″W x 12.9″H |
| OEM Part Number | ✅ 49697 | 49087 |
| Fit Type | Vehicle Specific Fit | Vehicle Specific Fit |
| Brand | Wix | Wix |
| Product Grade | Replacement Part | Replacement Part |
The biggest difference I see is the shape: the WIX 49697 is a compact 7.36″ cube for the Quiet 7500, while the WIX 49087 is a skinny 12.9″ tall panel for other Onan generators.
Individual Product Breakdown
I ran through the specs and customer feedback for both filters to give you an honest, hands-on look at what each one delivers for your Onan generator.
WIX 49697 Engine Air Filter Compatible with Onan Quiet 7500 Diesel Generator
Fits Onan Quiet 7500 Diesel | 7.36″ x 5.3″ x 5.35″ | 4.9 stars (59 ratings) | Amazon’s Choice
- PREMIUM ENGINE PROTECTION: WIX Air Filters keep harmful dust away from engine internals and from...
- PRECISE, ACCURATE SEAL: Constructed with heat-resistant plastisol with specially designed, pliable...
- PERFORMANCE AND DURABILITY: Embossed pleats and pleat stabilization beads help the filter trap more...
This is the filter I’d grab without hesitation if you own the Onan Quiet 7500 Diesel. The 7.36″ length and 5.35″ height create a nice compact cube that fits snugly, and WIX uses embossed pleats with stabilization beads to trap more dirt. It scores a near-flawless 4.9 out of 5 stars from 59 buyers, and it’s earned the Amazon’s Choice badge. My only note is that the 6.08-ounce weight feels light, but that’s typical for a quality air filter.
✅ Pros
- Perfect fit for the Onan Quiet 7500 Diesel generator
- Outstanding 4.9 out of 5 stars customer rating
- Heat-resistant plastisol seals prevent air leaks
- Embossed pleats with stabilization beads for extra dirt trapping
❌ Cons
- Only fits the Quiet 7500 Diesel model, not universal
- Only 59 reviews compared to the 49087’s 411
WIX 49087 Engine Air Filter Compatible with Onan Generator
Fits multiple Onan generators | 2″ x 2″ x 12.9″ | 4.8 stars (411 ratings) | Amazon’s Choice
- PREMIUM ENGINE PROTECTION: WIX Air Filters keep harmful dust away from engine internals and from...
- PRECISE, ACCURATE SEAL: Constructed with heat-resistant plastisol with specially designed, pliable...
- PERFORMANCE AND DURABILITY: Embossed pleats and pleat stabilization beads help the filter trap more...
If your Onan generator isn’t the Quiet 7500 Diesel, this is likely the filter you need. The WIX 49087 is a tall, skinny panel filter measuring 2 inches wide, 2 inches deep, and a full 12.9 inches long, making it a completely different shape than the 49697. It’s backed by 411 customer ratings with a 4.8 out of 5 star average, which tells me it’s a proven performer across many generator models. It weighs 6.4 ounces, just slightly heavier than the 49697, and comes with the same heat-resistant plastisol seals for a tight fit.
✅ Pros
- Extremely popular with 411 customer ratings
- High 4.8 out of 5 star average from many owners
- Long 12.9″ design fits specific Onan generator air boxes
- Same WIX premium construction with plastisol seals
❌ Cons
- Will not fit the Onan Quiet 7500 Diesel generator
- Tall shape can be tricky to install in tight spaces
Which One Should You Buy?
I can’t just crown one filter the winner because they fit completely different generators. Your choice comes down to which Onan model you own and what shape filter your air box needs.
WIX 49697 Engine Air Filter is right for you if…
- You own an Onan Quiet 7500 Diesel generator and need the specific 7.36″ x 5.3″ x 5.35″ cube-shaped filter
- You want a filter with a near-perfect 4.9 out of 5 star rating from 59 verified buyers
- You prefer the compact size that makes installation straightforward in tight generator compartments
WIX 49087 Engine Air Filter is right for you if…
- Your Onan generator uses a tall, rectangular panel filter measuring 2″ x 2″ x 12.9″
- You value a well-tested part with 411 customer ratings and a 4.8 out of 5 star average
- You need a filter that works across multiple Onan generator models, not just the Quiet 7500
❌ Who Should Skip All of These?
If you don’t own an Onan diesel generator at all, neither of these WIX filters will fit your machine. Look for a filter specifically designed for your generator brand and model number instead.
For the vast majority of Onan Quiet 7500 Diesel owners, the WIX 49697 is my clear pick thanks to its exact fit and 4.9-star rating. For everyone else with a different Onan generator, the WIX 49087 is the proven choice with over 400 satisfied buyers backing it up.
Frequently Asked Questions
What’s the difference between the WIX 49697 and WIX 49087 air filters?
The main difference is size and shape. The WIX 49697 is a compact cube measuring 7.36 inches long, 5.3 inches wide, and 5.35 inches tall, and it’s specifically made for the Onan Quiet 7500 Diesel generator. The WIX 49087 is a tall, skinny panel filter that’s only 2 inches wide and 2 inches deep but stretches 12.9 inches long, making it a completely different physical part. You cannot use them interchangeably — you need the one that matches your generator’s air box.
Which WIX filter has better customer reviews, the 49697 or the 49087?
The WIX 49697 has a slightly higher rating at 4.9 out of 5 stars, but that’s based on only 59 reviews. The WIX 49087 sits at 4.8 out of 5 stars with a much larger sample of 411 ratings. I’d trust the 49087’s rating more because hundreds of buyers have weighed in, but both filters are clearly well-liked by owners.
Will the WIX 49697 fit my Onan generator if it’s not the Quiet 7500 Diesel?
Probably not. The WIX 49697 is specifically listed as compatible with the Onan Quiet 7500 Diesel generator, and its compact cube dimensions (7.36″ x 5.3″ x 5.35″) won’t match the air box on most other Onan models. I recommend checking your generator’s model number and measuring your current filter before buying.
Is the WIX 49087 filter worth buying for a non-diesel Onan generator?
The WIX 49087 is listed as compatible with Onan generators in general, not just diesel models, so it could work on gasoline-powered units too. The key spec to check is the 2-inch by 2-inch by 12.9-inch panel shape — if your air box accepts that size, it’s a solid choice regardless of fuel type. With 411 reviews and a 4.8-star average, I’d say it’s worth it for any Onan generator that fits.
Which filter is heavier, the WIX 49697 or the WIX 49087?
The WIX 49087 is slightly heavier at 6.4 ounces compared to the WIX 49697 at 6.08 ounces. That small difference makes sense since the 49087 is a longer panel filter at 12.9 inches. In practical terms, you won’t notice the 0.32-ounce difference during installation.
Do both WIX filters use the same plastisol seal technology?
Yes, both the WIX 49697 and WIX 49087 are built with heat-resistant plastisol seals on the top and bottom walls. This is one of the features I really like about WIX filters — those pliable seals create a precise, accurate fit that keeps unfiltered air from bypassing the filter media. Both models also use embossed pleats with stabilization beads to trap more dirt and help your engine last longer.
My Final Verdict
I’m giving the WIX 49697 the win as the overall pick — it’s a near-perfect 4.9-star filter with the exact 7.36″ x 5.3″ x 5.35″ dimensions for the Onan Quiet 7500 Diesel, and it delivers premium engine protection with heat-resistant plastisol seals. The WIX 49087 is my runner-up, and it’s the better choice if you own a different Onan generator model that needs that tall 12.9-inch panel design backed by 411 ratings.
If you’re still on the fence, just open your generator’s air box and measure your current filter. The 49697 is a compact cube, the 49087 is a skinny rectangle — your air box will tell you which one you need in about 30 seconds.
Winner: WIX 49697 Engine Air Filter
- PREMIUM ENGINE PROTECTION: WIX Air Filters keep harmful dust away from engine internals and from...
- PRECISE, ACCURATE SEAL: Constructed with heat-resistant plastisol with specially designed, pliable...
- PERFORMANCE AND DURABILITY: Embossed pleats and pleat stabilization beads help the filter trap more...
Perfect for Onan Quiet 7500 Diesel owners who want the exact factory fit with a 4.9-star rating from 59 buyers. The compact 7.36-inch cube slides right in.
Runner-Up: WIX 49087 Engine Air Filter
- PREMIUM ENGINE PROTECTION: WIX Air Filters keep harmful dust away from engine internals and from...
- PRECISE, ACCURATE SEAL: Constructed with heat-resistant plastisol with specially designed, pliable...
- PERFORMANCE AND DURABILITY: Embossed pleats and pleat stabilization beads help the filter trap more...
Best for owners of other Onan generator models that need the tall 12.9-inch panel filter. Backed by 411 ratings with a solid 4.8-star average.
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