Product Reviewed: SAE 0W-40 Signature Series 100% Synthetic Motor Oil (AZF)
Current Rating: 4.97 out of 5 stars
Votes & Reviews: 51 vote(s) and 967 user reviews.
Reviewed by K-Mac: 
I only use American AMSOIL in all my vehicles. For this one, I use it in my 2005 Honda Fit 1500cc..
Reviewed by K-Mac:
I only use American AMSOIL in all my vehicles. For this one, I use it in my 2016 Nissan Caravan NV350.
Reviewed by Jeff:
I run Amsoil oil and filter in my Yukon Denali 15,000 miles between changes. Just reset the change oil message at 7500. Doing this for years with several GMC Yukon's. At 250,000 plus miles no oil burn at all. Very impressed with not having to go under the car twice as much.
Reviewed by Ricky:
Awesome cold start protection, and anti-wear lube, simply the best
Reviewed by Mustang Larry:
So far all is good.
Reviewed by Mustang Larry:
Why is it when I change my oil does my mileage drop by 2mpg. For the first 400 miles 1 1/2 to 2 mpg less then it creeps back up.
Reviewed by Ron the Tyrolian:
I have relied on Amsoil products for years to protect my engines and it has done exactly that.
Reviewed by SamLac:
I started using AMSoil in the mid 80s while in Alaska. Cold extreme make lubrication very critical. At minus 40, most petroleum lubes won't even drip off the dip stick and when started cold you can hear every bearing in the engine as there is little or no lube flowing. No so with my AMSoil.
Reviewed by Jeff:
I've been running 5W30 Signature Series in my 2002 Tacoma since putting it on the road in 2016 with 116,000 miles on the engine. I have since had Oil Analyzers (Amsoil, Inc.) test three samples from the truck so far, and have yet to have the oil last more than 13K miles before being told it's time for it to be changed. So much for the 25,000 miles/1 year claim...
Reviewed by Grizz:
I have 2 vehicles that have had this oil in them (changed every 15,000mi) since I bought them new. They both have mileage approaching 250,000, and they run like BRAND NEW. My newest vehicle is a 2017 Subie Forester Turbo so it gets Signature 5W-30 every 10,000 miles, and I'm sure it will see 200k and beyond.
Reviewed by GF1563:
Love the extended oil change intervals and my fuel mileage increased slightly, which leads me to believe it must be lubricating everything very well.
Reviewed by Pat:
It's great year round hot or cold
Reviewed by Don:
Several years ago I switched to Amsoil in my GMC Yukon. I was very impressed with what the Signature Series 5w-30 Motor Oil looked like after the first oil change. With all the oils and products that Amsoil offers, I have since switched everything I own over to Amsoil. Even my lawnmowers.
Reviewed by dhgguy:
Used in my F150 exclusively. Excellent oil & filter.
Would not use anything else.
Reviewed by Ronv:
I have used Amsoil for 30 years and wouldn't think of using any other oil.
Reviewed by Mister nice:
Love that you don't have to change oil as offer as regular oil. Is is a little high. Hey but you get what you pay for.
Reviewed by Henry:
I use Amsoil exclusively
Reviewed by Jblev77:
#1 for 3.5L ecoboost
Reviewed by Ed:
I like being about to change oil at any time between 5-10k and not have to worry about weather or not the oil is doing it job !!!
Reviewed by RebelnOhio:
I have been using Amsoil for over 15 years and have never had a problem, it's a well proven product that I trust in all of my cars for work and for pleasure. I will will continue to use Amsoil and benefit from it's proven results! I own a Livery/Limo Service and I drive about 40-50K miles a year on various cars and I believe Amsoil is the best Oil for all of my vehicles. With the long 15k Mile change intervals it is a money saving gem and your engine benefits 100%. I recommend there products highly!
Reviewed by KENT:
I've used this brand and series in my Dodge Ram 4.7 v-8 since I acquired it at 90,000 miles. I've driven another 70,000 miles since and the engine is stronger than it's ever been! I expect to drive this truck until at least 300K miles because of the Amsoil Signagture Series Synthetic brand motor oil. I won't use anything else!
Reviewed by KK:
I use Amsoil on my SUV and love it!
Reviewed by Tom:
I use ansoil on all of my trucks, motorcycles, ATVs. This oil I use on 2017 Hemi 2500. It cannot be beat.
Reviewed by G:
Instant satisfaction, after the first start up i could already hear and feel things running smoother.
Reviewed by Redtundra8:
This is the best oil money can buy in my opinion. I use this in all my vehicles and have for the last 12 years. Love only having to change the oil once a year. I highly recommend this product.
Reviewed by Pat:
Bestboil products on the market by far. I run it in all my vehicles
Reviewed by Billy G:
I have used Amsoil products for many years in all of my vehicles and small engines. I have never had an issues. I recommend Amsoil even though it is not the cheapest but the delivery is very prompt.
Reviewed by Wingsprnt:
Not sure about the oW-20 weight here in Florida, but that is what Honda calls for.
Reviewed by Greg:
Always met my expectations.
Reviewed by MatsB:
Using Amsoil in all of my family's cars. Using Signature series in cars that drive over 12,000 miles per
year, and XL series in cars that drive less than 12,000 miles.
Sent a 27,000 mile sample for testing to a independent lab, and they recommended 30,000 miles next time based on the excellent results.
Also using Amsoil in all lawn equipment and for a standby generator.
Reviewed by Robert Long:
Great product gives better fuel mileage and cleaner oil after changes
Reviewed by Tim:
I've been using Amsoil since the 1980s in everything with an engine. And have bragged about it's benefits to anyone who'd listen.
Reviewed by Rob:
I get better mileage with Amsoil
I run my 4x4 very hard and Amsoil is doing a great job of keeping it running strong
Reviewed by Elvis of Aragorn:
My 2004 Silverado (5.3L V8) has had a steady diet of Amsoil since its second oil change. I have stuck to the 10,000 mile interval, using Amsoil Ea filters & Signature Oil. She's about to roll over the 200,000 mile mark, and I have had no engine issues. I use Amsoil Signature Synthetic Oil in all of my vehicles, and plan on keeping it that way.
Reviewed by Pinto:
I'm city driving in a 4x4 Ford van and after my last oil change the oil was still in great condition after 15,000 miles. just used the cleaning solution so lets see how this improves engine longevity. really happy with all th products I have received.
Reviewed by S2kadi:
I use Amsoil Signature Series in both of my cars that are susceptible to burning oil. The 10W30 goes into my Honda S2000 and works great! Amsoil is the only oil I use in my motors and gearboxes, after trying out several different brands, I have found their quality to be of the best.
Reviewed by pro4100:
I use it in my Subie Forester and my silverado 1500. no problems ever!
Reviewed by Quick charge water:
Yeah like to 25,000 my old changed
Reviewed by Beast:
I will never use conventional again. 10K mile Oil changes, or once a year. You cant beat the quality and value of this product. No dealer or mechanic can ever persuade my to change every 3k miles again!. Get you some!
Reviewed by ScoobyVTEC:
Bought Amsoil for all of my cars so I wouldn't have to change the oil so frequently and for the protection it gives all of the internal moving parts. I've noticed
an increase in MPG and smoothness when I drive.
2017 Civic Type R
2012 Pilot Touring AWD
1998 Civic EX
Reviewed by S & S Performance:
Some of the best oil I have ever used. I tow a 10k lb trailer and oil temps even in dead of summer stay very low. Would definitely recommend to anyone.
Reviewed by S & S Performance:
Some of the best oil I have ever used. I tow a 10k lb trailer and oil temps even in dead of summer stay very low. Would definitely recommend to anyone.
Reviewed by Joseph:
Just built a blown LS 383 stroker for my 05 sierra. I have used other synthetics in the past, my builder recommended amsoil and i took his advice. Also use in my 70 nova SS with a stroker 496
Reviewed by Iowa Veteran:
No complaints on the product although a free hat for my 2nd or 3rd review of AMSOIL products would be nice. (Not so subtle hint) Lol. I will say that packaging and delivery of seven quart bottles is always well done and delivered in a timely manner.
Keep up the good work.
Reviewed by Curt:
I like this product because we're always on the road and we need a heavy duty oil to withstand the punishment that we put it through in our trucks.
Reviewed by Dan:
I've used Amsoil in my vehicles for many years now. Filters also. I feel it's the best for my vehicles and that gives me peace of mind.
Reviewed by Carl:
I have used amsoil on my jeep srt8 2006 for 10 years. I have never had engine issues and I change my oil every 15,000 miles. If you need a good dependable oil for your performance vehicle, 0w-40 is the way to go.
Reviewed by David:
I use this oil in ram 6.4 hemi I town a 25ft snowmobile trailer and 30ft travel trailer and I have had no problems. I have never had to add oil between changes.
Reviewed by Super dave:
I use this oil in ram 6.4 hemi I town a 25ft snowmobile trailer and 30ft travel trailer and I have had no problems. I have never had to add oil between changes.
Reviewed by CBR 322:
Use in 2004 boxster S racecar. Awesome product. Last the whole enduro weekend without worry. Usually 15 hour endurance race.
Reviewed by Lamar:
It's the only brand I'll trust in my turbo vehicle. Oil seems to maintain it's qualities great and the old stuff still feels good when changing after 6,000 miles.
Reviewed by Stemal:
My engine runs cooler, oil pressure is 6 to 8 pounds higher couldn't be happier!!!
Reviewed by Nic:
I have read on a number of websites and have heard over the years that Amsoil is the gold standard for motor oil. I finally registered for an account and am now using Amsoil Signature 0W-40 in my 2016 Ram 2500 6.4L
4x4. I switched to Amsoil at 500 miles and have just recently changed the oil again at 6000 miles. I have been getting reasonable mileage with my new truck (about 14.5 mpg average), considering I have the 6.4L and it's a 4x4. I recommend that if you plan to use Amsoil, to pay the small amount to become a Preferred Customer (currently $20 per year), because it will pay for itself in the savings per quart of oil (about $12.50 to $8.50 for the 0W-40 Signature Oil).
A quick story ... I turned a friend on to Amsoil, he started using 5W-30 Signature in his 2007 Nissan Quest with 60,000 miles. As early as the drive home from my house after changing the oil, his 15 year old son with a learner's permit could feel it running smoother and quieter, and now only one month later, he is already seeing 1-2 mpg increase in fuel economy. He plans to change his oil again at about 5000 miles and will then change it annually.
Reviewed by Homer:
I have been using AMSOIL for 19 years now and wouldn't use anything but. I use this new 0w40 in my 2015 Challenger SRT 392. And have been using it now over the 5w30 in my old 2004 Ram 5.7 HEMI that has 193,000 miles on it all with AMSOIL.
The truck is running totally on AMSOIL products bumper to bumper. The challenger soon will also be covered with AMSOIL, But for now, just the engine.
My motor home, Jeep, and two KTM dirt bikes as all run with AMSOIL.
AMSOIL just can't be beat. And all of their products can be trusted to have what you drive running at its best.
Thanks AMSOIL
Reviewed by Mconniff:
I have spent most of my life using Mobile 1 products. When I found out that Mobile 1 didn't make oil for my new truck, I was at a loss. I do not like the oil brand (Pennzoil) that my dealership is pushing on me, Them: "You have to get your oil changes here because that is the only oil that you can use in your truck." Me: "Really? You're saying that Pennzoil is the only manufacture that makes a 0W-40 that meets the requirements of Ram... Challenge accepted." After doing some research on the Formula 1, NASCAR, NHRA race cars. Sending out e-mails and one hand written letter. My list was narrowed down to three manufactures. I currently have roughly 4k miles on my first AMSOil change. Once I get to 8k I will change it out and look at color, odor, and viscosity (how it feels) and compare it to some new oil. Then dissemble the oil filter. I am planning on ordering more oil because I feel once won't be enough to make a good judgement. However everything I have read and heard about AMSOil gives me reason to keep with this brand.
Reviewed by Mack:
Spec. oil that is required for my SRT Jeep.
Reviewed by SRTcolin:
I've used this in my daily driven SRT 8 for 10K miles, Blackstone oil sample came back with great results and they suggested I could go longer.
Reviewed by 300:
OIL AND AMSOIL OIL FILTER SEEMS LIKE A GOOD COMBO. Everytime I do a oil change oil comes still looking good not dark black like other brands.
Reviewed by Chris:
I use it in my 392 hemi and love how it keeps the hemi smooth as butter
Reviewed by Big Dawg:
I use this oil in my cars. This oil is the best I have ever used. My engine runs very quiet and I get better gas mileage using this oil. I will never use another oil. Amsoil signature series is fantastic. Thank you Amsoil!!
Reviewed by Kevin:
Great stuff!
Reviewed by Sean:
I use this oil for my Dogde Ram 2500 with the 6.4 hemi. The new 6.4's that Chrysler has out now takes 0w-40 oil. There's very few oil manufactures that make 0w-40. Since my truck was brand new only used Amsoil and love it. Wouldn't run anything else. Put just under 7500 miles on oil before changing, was still clean and not broken down. If you own a 6.4 hemi I would run Amsoil.
Reviewed by Hemi guy:
Second oil change coming up on my 2015 2500 dodge truck 392 hemi i'be used a lot of different oil a soil is the best by far
Reviewed by BootCampBob:
There are a lot of good synthetic engine oils on the market, but none better than Amsoil. I've been using it in all of my vehicles for seven years now, and haven't had any type of engine issues related to wear.
No, it's not the least expensive synthetic oil, but I don't "cheap out" when it comes to taking care of my cars. Only the best oil and filters for my machines. It's cheap insurance for my Hellcat.
There's really nothing more that needs to be said.
Reviewed by Joe:
Used in a 2015 Ram 2500, 6.4 Hemi. No tics,
Slightly better fuel economy.
Reviewed by No:
I use amsoil in my hellcat it quite at my lifters and seems to add more smooth power
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United States
A Trusted Product
I have been using Amsoil products in my vehicles and motorized equipment for many years and relay on its quality. As a "gearhead", I know how important using quality motor oils and greases are to machinery. They are my first choice for lubrication fluids.