Purple Seat Cushion Review: The Grid Cushion in Your Car

A car seat is shaped for the average driver, not for you — and after an hour behind the wheel, that gap shows up as stiffness, fidgeting and a sore backside. A purple seat cushion is a simple fix: a layer of cushioning that sits on the seat base and changes how the seat feels, without changing the car. The Purple Double Seat Cushion is the best-known version of the idea, built around the Purple Grid — a flexible honeycomb layer that the maker describes as pressure-reducing — and this review compares it with two memory foam alternatives.

The short answer: the Purple Double Seat Cushion is a two-sided grid cushion, 18 by 16 inches and 2 inches thick, that the maker designed for office chairs — and it fits many car seats well, because a car seat base is about the same size as an office chair seat. The kingphenix memory foam cushion is the car-first alternative, and the Everlasting Comfort is the washable one. None of the three is a medical device, and none of them is presented here as one.

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Quick Pick: Purple Seat Cushion and Two Alternatives

Purple Double Seat Cushion: The Grid Hero

The Purple Double Seat Cushion is the hero of this review, and it is also the odd one out: the listing describes it as a seat cushion designed for office chairs, not for cars. It is the Purple Grid made portable — a flexible honeycomb layer that the maker describes as pressure-reducing, built to spread weight across the seat instead of concentrating it in one spot. The cushion is two-sided, with a softer side and a firmer side, so you flip it to change the feel. It measures 18 by 16 inches and 2 inches thick, weighs 5 pounds, and the model number is DP-001. It is made in the USA and sold by Purple Innovation.

The reason a purple seat cushion designed for an office chair works in a car is size: a car seat base is about the same size as an office chair seat, and at 18 by 16 inches the Double sits on most car seat bases without hanging over the edges. The grid feels different from foam — it gives under weight and springs back, and air moves through the open honeycomb, which the maker presents as a cooler sit than solid foam. The two-sided design is the practical feature: the soft side suits a long sit, the firm side suits a driver who wants more support, and flipping the cushion is free. The weight is the trade-off: at 5 pounds it is a heavy cushion, and it is a cushion you carry, not one that lives in the car unnoticed.

One honest limit: the Purple Double has no straps, no non-slip base and no cover described in its listing, so it can slide on a smooth leather seat, and there is no removable cover to wash. It is also the cushion in this review with the least car-specific design — the kingphenix below was made for car seats, and the difference shows in the shape. But if you want to try the Purple Grid in your car, this is the cushion to try it with: the same grid Purple puts in its mattresses and office chairs, in a size that fits a car seat.

Purple Double Seat Cushion on Amazon: pressure-reducing grid, two-sided soft and firm, 18 x 16 x 2 inches, 5 pounds, model DP-001, designed for office chairs, made in the USA.

Buy the Purple Double Seat Cushion if: you want to try the Purple Grid in your car, you like the idea of flipping the cushion between a soft side and a firm side, and your car seat base measures at least 18 by 16 inches. Measure the seat first — a small or heavily bolstered seat may not fit it.

kingphenix Memory Foam Cushion: The Car-First Purple Seat Cushion Alternative

The kingphenix cushion is the car-first alternative in this review: a memory foam seat cushion made for car seats and office chairs, in that order. The listing calls it a car seat cushion first, and the shape shows it — it measures 20 inches long by 19 inches wide by 1.2 inches thick, which is longer and wider than the Purple Double but much thinner, so it lifts you less and fits under a seat belt more easily. The materials are breathable fabric over polymer memory foam, and the colour in this review is black. The model name is Memory Foam Car Seat Cushion, and the part number is Car seat cushion-B and G.

The thinness is the feature that matters most in a car. A 2-inch cushion like the Purple Double raises you noticeably on the seat, which can change your driving position and your view over the wheel; a 1.2-inch cushion changes the feel of the seat without changing your position much. The memory foam works the way memory foam always works: it softens with body heat and moulds to your shape, then slowly returns when you get out. The listing describes the cushion as designed for drivers and other people who sit for long periods, and the breathable fabric cover is part of that — a cushion that traps heat is a cushion you stop using in summer.

The trade-off against the Purple Double is the feel: memory foam is a slow, sinking comfort, while the grid is a springy, open one, and neither is better in the abstract — it is a preference. The kingphenix is also the cushion to watch for wear: thin memory foam can compress over time, and the listing gives no washable-cover claim for this model. But as a seat-cushion alternative made for driving, it is the most honest fit in this review: the right shape and the right thickness.

kingphenix Car Seat Cushion on Amazon: breathable fabric and polymer memory foam, 20 x 19 x 1.2 inches, for car and office chair, black, model Memory Foam Car Seat Cushion.

Buy the kingphenix cushion if: you want a cushion made for car seats, you do not want a thick cushion changing your driving position, and you prefer memory foam to a grid. Check the 20 by 19 inch size against your seat base — it is the largest of the two cushions with stated dimensions in this review.

Everlasting Comfort Memory Foam Cushion: The Washable Purple Seat Cushion Alternative

The Everlasting Comfort cushion is the washable alternative in this review: a memory foam seat cushion for office chairs and cars, made from 100 percent high-density memory foam with a removable, machine washable, slip-resistant cover. The listing describes it as a multiuse cushion — desk chair, car seat, wheelchair — and the size in this review is Large, in black mesh. The maker is Upper Echelon Products, and the model name is Multiuse Seat Cushion for Desk Chair, Car Seat Cushion, Wheelchair, Automotive cushion.

The washable cover is the feature that matters in a car. A car seat cushion collects crumbs, dust, sweat and coffee, and a cushion you cannot clean is a cushion you eventually throw away. The Everlasting Comfort cover comes off and goes in the wash, and the slip-resistant base keeps the cushion from sliding on the seat — the two practical features the Purple Double does not offer. The foam is 100 percent high-density memory foam, and the listing says it is made with 30 percent more memory foam than the maker’s earlier cushion, which the maker presents as support for sitting 8 or more hours.

The listing is also the most careful of the three about what a cushion cannot do. It carries a disclaimer in its own words: the maker does not guarantee the cushion cures lower back, coccyx or sciatica pain. That disclaimer is worth repeating, because cushion listings often promise more than a cushion can deliver. This article makes no medical claim for any of the three cushions: they are comfort products, and comfort is a personal judgement, not a treatment. The Everlasting Comfort is the pick in this review for the driver who wants the easiest cushion to live with — washable, non-slip, and honest about its limits.

Everlasting Comfort Memory Foam Seat Cushion on Amazon: 100 percent high-density memory foam, removable machine washable slip-resistant cover, for office chairs and cars, black mesh, Large, model Multiuse Seat Cushion.

Buy the Everlasting Comfort cushion if: you want a cushion you can wash, you want a non-slip base so it stays put on the seat, and you prefer dense memory foam to a grid. Check the Large size against your seat base before you order.

Purple Grid vs Memory Foam: How the Cushions Feel Different

The Purple Grid and memory foam feel different because they are built differently, and the difference is the choice this review turns on. The Purple Grid is an open honeycomb: it gives under weight, springs back at once, and air moves through it, so the maker presents it as a cooler sit. Memory foam is a solid block that softens with body heat, moulds slowly to your shape, and returns slowly when you get up. The grid feels springy and open; foam feels slow and sinking. Neither feeling is better in the abstract — drivers who like a firm, responsive seat tend to prefer the grid, and drivers who like to sink into the seat tend to prefer foam.

The practical differences follow the feel. The grid is 2 inches thick and weighs 5 pounds, so it changes your driving position more and is heavier to carry between cars. The memory foam cushions are thinner or denser, and the kingphenix at 1.2 inches barely changes your position at all. The grid has no cover to wash; the Everlasting Comfort cover comes off and goes in the wash. And the grid is two-sided — soft on one side, firm on the other — while the foam cushions have one feel each. Try the grid if you want to feel something different from every foam cushion you have sat on; try the foam if you already know you like it.

If you want the direct head-to-head, our Purple vs kingphenix seat cushions comparison puts the grid and the memory foam side by side; this review goes deeper on the Purple Double itself, its size and fit, and how to live with it day to day.

Purple Seat Cushion Sizing: Will It Fit Your Car Seat?

A purple seat cushion only works if it fits the seat, and the three cushions here are three different sizes. The Purple Double is 18 by 16 inches; the kingphenix is 20 by 19 inches; the Everlasting Comfort in Large is a similar large size — check the listing for the exact dimensions of the size you order, because the maker sells several sizes under the same listing. Measure your seat base before you order: the width between the side bolsters, and the depth from the seat back to the front edge. A cushion wider than the bolsters will ride up on them and feel lumpy; a cushion longer than the seat will hang over the front edge and curl.

Some buyers find the Double adds too much height or does not cover the seat — measure first.

Thickness matters as much as footprint. A 2-inch cushion like the Purple Double raises you two inches, which changes your view over the wheel, your reach to the pedals and the way the seat belt sits across you. A 1.2-inch cushion like the kingphenix barely changes any of that. If your car seat is heavily bolstered — sports seats, for example — a flat cushion will never sit well, and a contoured cushion made for car seats is the better bet. And if your car has seat covers, check the fit with the cover on: our best seat covers guide covers full-set covers, and a cushion on top of a cover can slide more than a cushion on bare upholstery.

How to Use a Purple Seat Cushion in Your Car

Using a purple seat cushion in a car takes a minute, and the order matters. Put the cushion on the seat base first, flat and centred, with the front edge lined up with the front of the seat. Sit on it and check your driving position before you drive: your feet should reach the pedals without stretching, your eyes should clear the wheel, and the seat belt should sit across your lap and chest the way it did without the cushion. A cushion that changes your position changes your safety, and a seat belt that rides up on a thick cushion is a seat belt that will not hold you right.

Then drive a short trip before a long one. The grid and the foam both feel different after twenty minutes than they do after two, and a cushion that feels fine on a test sit can feel wrong on a long drive. If the cushion slides on a leather seat, a non-slip mat underneath helps — the Everlasting Comfort has a slip-resistant base built in, and the Purple Double does not, so it is the one most likely to need help. Keep the cushion in the car between trips if you drive daily; carry it in if you park in the sun, because a dark cushion left in a hot car gets hot — and Purple warns that extreme heat can warp the grid and that heat damage may void the 1-year warranty, so do not leave it baking in a parked car.

Caring for a Purple Seat Cushion

A car seat cushion lives a harder life than an office cushion: dust, crumbs, coffee and sun, every day. The Everlasting Comfort is the easiest of the three to care for, because its cover is removable and machine washable — take it off, wash it, put it back on, and the cushion is clean. The kingphenix has a breathable fabric cover, but the listing for this model makes no washable-cover claim, so check the listing’s care instructions before you wash it. The Purple Double has no cover described in its listing at all, so treat it as a wipe-clean cushion and check the listing’s care instructions before you do anything else.

For all three, the same habits help: shake the cushion out regularly, vacuum it when you clean the car, and keep it out of direct sun when the car is parked — sun fades fabric and dries out foam over time. If your seats need a deeper clean, our how to clean car seats guide covers the seat underneath the cushion, and our best car seat cleaner guide covers the cleaners worth using on upholstery. A cushion is not a substitute for cleaning the seat — it sits on top of it, and a dirty seat under a clean cushion is still a dirty seat.

Purple Seat Cushion Mistakes to Avoid

The most common purple seat cushion mistake is buying without measuring the seat. An 18 by 16 inch cushion on a narrow or heavily bolstered seat rides up and feels lumpy, and a 20 by 19 inch cushion on a small seat hangs over the edges. The second mistake is buying a cushion for a medical problem: no cushion in this review is a medical device, and the Everlasting Comfort listing says so in its own disclaimer — the maker does not guarantee the cushion cures lower back, coccyx or sciatica pain. If you have a medical condition, talk to a clinician, not a cushion listing.

The third mistake is ignoring the driving position. A thick cushion raises you, changes your reach to the pedals and changes how the seat belt sits — check all three before a long drive, not during one. The fourth is leaving a dark cushion in a hot parked car and sitting on it without checking: it gets hot. The fifth is assuming the grid does the work by itself — a purple seat cushion changes how the seat feels, and a bad seat with a cushion on it is still a bad seat. And the sixth is buying the Purple Double for the car without noticing the listing says it was designed for office chairs: it fits many car seats, but it was not shaped for them, and the car-first kingphenix exists for exactly that reason.

Who Should Buy a Purple Seat Cushion — and Who Should Not

Buy a purple seat cushion if: you drive long distances and your car seat feels hard, flat or unsupportive after an hour. A cushion is a cheap way to change how a seat feels without changing the seat, and the grid and the foam both offer a different sit from bare upholstery. If your passenger is a dog rather than a person, the cushion is the wrong tool — our dog car seat review covers the booster that lifts a small dog to window height instead.

Buy one with care if: your seat is small, heavily bolstered, or leather-smooth. Measure the seat base, check the cushion size against it, and expect a flat cushion to slide on smooth leather unless it has a non-slip base. Try the cushion on a short drive before a long one.

Do not buy a purple seat cushion if: you are looking for a treatment for back or tailbone pain, or your car seat already fits you well. A cushion is a comfort product, not a medical device, and a seat that fits needs no cushion on top of it. If the seat is the problem, the honest fix is a better seat or a different car, not a layer on top of a bad one.

The Verdict

The best purple seat cushion is the one that fits your seat and your idea of comfort. The Purple Double Seat Cushion is the pick for trying the grid: a two-sided cushion, soft on one side and firm on the other, in a size that fits many car seats even though the maker designed it for office chairs. The kingphenix is the pick for the driver who wants a cushion made for cars: thin, wide, memory foam, and barely changing the driving position. And the Everlasting Comfort is the pick for the driver who wants the easiest cushion to live with: dense memory foam with a washable, non-slip cover, and a listing honest about what a cushion cannot do.

For the head-to-head verdict between the Purple grid and the kingphenix foam, see our Purple vs kingphenix seat cushions comparison.

Whichever cushion you choose, check two things before you order: the size against your seat base, and whether the listing still shows a live offer — listings change, and a listing that showed an offer when this review was researched may not show one now. Measure the seat, try the cushion on a short drive, and check the seat belt still sits right. A cushion is a small piece of kit, but on a long drive it is the difference between arriving stiff and arriving comfortable.

Frequently Asked Questions

Is the Purple seat cushion made for cars?

Not exactly. The Purple Double Seat Cushion listing describes it as designed for office chairs, and the maker sells it as an office chair cushion. It still fits many car seats, because a car seat base is about the same size as an office chair seat, and at 18 by 16 inches it sits on most car seat bases without hanging over the edges. If you want a cushion made for car seats from the start, the kingphenix in this review was made for car seats and office chairs, in that order — measure your seat base either way before you order.

What is the Purple Grid?

The Purple Grid is the flexible honeycomb layer inside Purple cushions and mattresses. The maker describes it as pressure-reducing: the grid gives under weight and spreads it across the seat instead of concentrating it in one spot, and air moves through the open honeycomb, which the maker presents as a cooler sit than solid foam. The Double Seat Cushion is two-sided, with a softer side and a firmer side, so you flip it to change the feel. This article repeats the maker’s description of the grid and makes no claim about the grid beyond what the maker states.

Will a purple seat cushion fit my car seat?

It depends on the size. The Purple Double is 18 by 16 inches and 2 inches thick; the kingphenix is 20 by 19 inches and 1.2 inches thick; the Everlasting Comfort in Large is a similar large size, so check the listing for the exact dimensions of the size you order. Measure your seat base — the width between the side bolsters and the depth from the seat back to the front edge — and compare it with the cushion. A cushion wider than the bolsters will ride up on them, and a cushion longer than the seat will hang over the front edge.

Can I wash a purple seat cushion?

It depends on the cushion. The Everlasting Comfort has a removable, machine washable cover, so it is the easiest of the three to clean — take the cover off and wash it. The kingphenix has a breathable fabric cover, but the listing for this model makes no washable-cover claim, so check the listing’s care instructions before you wash it. The Purple Double has no cover described in its listing, so treat it as a wipe-clean cushion and check the listing’s care instructions before you do anything else.

Purple seat cushion vs memory foam — which is better?

Neither is better in the abstract — they feel different, and the choice is a preference. The Purple Grid is springy and open: it gives under weight, springs back at once, and air moves through the honeycomb. Memory foam is slow and sinking: it softens with body heat, moulds to your shape, and returns slowly when you get up. Drivers who like a firm, responsive seat tend to prefer the grid; drivers who like to sink into the seat tend to prefer foam. If you already know you like memory foam, the kingphenix or the Everlasting Comfort is the safer buy; if you want to feel something different, try the Purple Double.

Does a purple seat cushion help on long drives?

A cushion can make a long drive more comfortable by changing how the seat feels — adding softness, spreading weight, or raising you slightly — and many drivers use one for exactly that. But no cushion in this review is a medical device, and none is presented here as a treatment for back, tailbone or any other pain: the Everlasting Comfort listing states in its own disclaimer that the maker does not guarantee the cushion cures lower back, coccyx or sciatica pain. If you have a medical condition, talk to a clinician. For comfort alone, try the cushion on a short drive first, and check the seat belt still sits right.