Idemitsu is my go-to brand for OEM spec fluids. Rumor has it, they make a lot of the OEM stuff. Great stuff regardless. Been using them in place of Honda branded products for decades without any issues.
Reviews of IDEMITSU parts For Business
Japan
I buy 5 OE Toyota filters at a time from Amazon ( approximately $6 ea ) Purchase Ow-20 Idemitsu oil from NAPA ( ships free to my home ) in the cost saving 6gal box ( 24 qts ) for about $125 with their online coupon. Use this in both my Avalon and my Tundra- both run like a dream.
This is normal. Wait till it gets below 1k rpm. Modern engines do not need a lot of time to idle after cold start, the ECU handles it. Although, for a few kilometres, do not push very hard. The engine oil (0w-20 idemitsu) is thin, and needs time to lubricate well.
I have a 17 grand touring and I use idemitsu 0w/20 and purolator b9ss filters.
I went with Idemitsu fluid on mine which 12 quarts cost me 145 at NAPA.
Switch to Idemitsu ( Japanese oil ) - Manufacturers for genuine and even does factory fill for many, they are very premium oils with starting segment already beating the top shelf of alternative brands.
Idemitsu 05-W30 from Unioil kasi I cant find Castrol for my Mazda
Idemitsu is responsible for the oil that powered the Mazda 787b; they know the rotary like no other. I exclusively use their synthetic 20w50 and premix.
Regarding brands, if you want to stick with factory oil without dealer price, Idemitsu is the brand to get. I emailed Mazda corporate and they said Idemitsu is the OEM for their oil.
So if you review the virgin oil analysis database, it includes idemitsu 0w-20 and 5w-30 and for both, the TBN is rather weak in comparison to other more readily available blends, also, the viscosity at 9.5 cSt for a 30w, some 20w come close to that. Does any of that matter? Not a whole lot, but it shows that there's nothing special about the oil. Generally speaking, higher TBN is better.
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Owner reviews of IDEMITSU products
The IDEMITSU brand is registered in Japan. Official website is not specified yet.
In March 2026, PartReview recorded 32 reviews across 3 parts by IDEMITSU. Average rating — 4.6 out of 5.
IDEMITSU is in the PartReview manufacturers ranking, currently at position 7. Over the last 30 days it dropped by 0 points.
Popular IDEMITSU parts
The most popular IDEMITSU products on PartReview:
- Engine oil IDEMITSU - 28 reviews. PR Score — 97, average rating — 4.8.
- CVT fluid IDEMITSU - 3 reviews. PR Score — not available yet, average rating — 4.
- Power steering fluid IDEMITSU - 1 review. PR Score — not available yet, average rating — 5.
Most owner reviews about IDEMITSU parts are collected on these pages.
Top-rated IDEMITSU parts
IDEMITSU achieved top positions in these PartReview part rankings:
- Best engine oil — ranked 14 among 32 manufacturers. Received 12429 votes.
Comparisons of IDEMITSU parts
The most interesting comparisons of IDEMITSU with other manufacturers help you see which is better: