Product Reviewed: SAE 5W-50 Signature Series 100% Synthetic Motor Oil (AMR)
Current Rating: 4.97 out of 5 stars
Votes & Reviews: 58 vote(s) and 971 user reviews.
Reviewed by Railrunner: 
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.
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 Tadd:
Hold up to heat and high horsepower well withought having a high viscosity in cold weather!
Reviewed by Chris:
Amsoil is a superior product. I use it on all my vehicles and every time I convert a vehicle to amsoil it always runs smoother then it was prior to the swap.
Reviewed by Nightw50:
I use this oil in my 1.6L off road car here in the Arizona heat. It runs quieter and smoother than anything I've used. In these severe conditions it excels beyond my expectations.
Reviewed by Ricky:
I use Amsoil on all my vehicles and equipment
Reviewed by Drew:
The new formula is working out very well in our ecoboost applications.
Reviewed by Juan:
Drive 1 hour Clermont to Orlando back and forth every weekday. Already 300,000 miles. My car responds like a new car.
There are 5 cars in our household. I had to change oil 4 times a year per car. That was 4x5=20 oil changes. Now I change oil once a year, usually on the same day!
Reviewed by Silver:
Use in competition ski boat 60-120 degrees .
Reviewed by coyote man 740hp:
i run this in my track pack 2014 mustang GT with a Paxton supercharger , the car makes 740whp and the oil lasts well over 12,000 miles and i dint tack it easy on this car , i drive it very hard and the oil really protects my 5.0 even at this power level . only oil i will use from now on !!
Reviewed by John R:
I have a friend that use it for his Ford Mustang
Reviewed by SRT WHO:
Simply the best oil on the market. Only oil I use on my 2014 GT 500 with over 1k rwhp
Reviewed by HotRod:
AMSOIL formulated this oil specifically for my Ford Coyote V8 engine, why would I use anything else? My vehicle is heavily modified for performance, I need the highest performing motor oil available and from the research I have made on my own that oil is AMSOIL. I am an engineer by profession, I want things to be precise and exacting, that's what I get with AMSOIL.
Reviewed by Moe:
Great product used it in a very high mileage vehicle haven't had any issues
Reviewed by Norcalcobra:
I use this in my gt500. I push the car hard knowing Signature Series has got me covered.
Reviewed by hollywood:
always recommend this stuff
Reviewed by Outlaw mike:
Car runs strong and smooth
Reviewed by Willy:
Use it on my 1995 Chevrolet Camaro z28
Reviewed by Dave:
Wouldn't use anything else in my new Focus RS! I run Amsoil in all my toys! Cars, Ducati's, and waverunner!
Reviewed by Musicman:
I use it a 1998 CHEVY VAN WITH 200,000 MILES.rUNS GREAT ,EASY STARTS ON -30 DEGREE WEATHER WITH INSTANT OIL PRESSURE.
Reviewed by Mike:
I use this product in my 1989 Toyota pickup truck. This truck has 360,000 miles on it and is going strong. I also use Amsoil in all of my other vehicles and would not consider anything else.
Reviewed by Dman:
I run a fleet of vehicles and we use Amsoil in all of our vehicles. We get great life from all of them.
Reviewed by Gaylord:
This product was used in a Ford Mustang GT CS
Reviewed by CM6248:
I use this oil in my vehicle because it meets my manufacturer''s specifications. Also, I noticed after about a hundred or so miles that a nuicanse tick went away.
Reviewed by Mgizzle:
Put it in my track camaro, 2013 SS 1LE, last year april so 2015. Had about 4 track day HPDEs then car stored for 6 winter months, metro detroit michigan, unheated garage. Took car out this april did 2 veeery hard track days on same oil, hit 300f on oil with average around 295F for 6 20 minute sessions.... Total now 3500miles for a year on amsoil filter. Sent for lab analysis to blackstine labs oil was in great conditions no issues. Put another 8 in the ls3!!!
Reviewed by Boss302Guy1223:
I have swapped all 3 vehicles to amsoil SS motor oil
Reviewed by capt. kirk:
this oil has been synthetic for a long time .I was just waiting for 5w-50 to come out.
Reviewed by BShep:
This is the only product I trust in my 738hp 2013 Boss 302 Mustang. This is my daily driver and play toy. The signature series has great life in my supercharged application which makes the comparable pricing a bargain!
Reviewed by Grabber Blue Greggor:
My '13 Boss 302 takes an odd oil grade....5W-50...and only a few brands offer it...and when they do it's usually formulated for older Muscle cars....so it's loaded with Zinc additives...very detrimental to modern catalytic converters....plugs them up.
AMZOIL created their Signature 5W-50 specifically to address Fords running the HO versions of the newer 5.0 V-8s !
The Boss loves it for Breakfast and never Burps. Thanks AMZOIL!! Super Product!
Reviewed by MacGyver:
Finding a rare viscosity like 5w50 in a synthetic oil is difficult. I was very glad to find it in Amsoil, a company well known and trusted for it's excellence in quality. The BMW R1200GS with it's high-compression engine, is an adventure motorcycle built to go anywhere from Siberia to the Sahara. Using Amsoil Signature Series 5w50 100% Synthetic provides improved lubrication at start-up and excellent operating protection in all temperature ranges. Because the BMW R1200GS uses a dry clutch, the options for motor oil are broader than using only motorcycle oils. Signature Series 100% Synthetic Motor Oil (AMR) is the perfect oil for my machine and will be the only oil used from this point forward. Thank you for providing shipping within Canada to avoid the hassle and expense of ordering from outside the country.
Reviewed by Dave Scott:
Thank you amsoil for making a 5w50 oil. Being a rare viscosity OEM's charge premium price whilst the performance is no where near premium. Now with amsoil signature series 5w50, I get better price and great performance and extended drain intervals. A true winner.
Re: Thank you - 2014 FORD MUSTANG 5.8L
Thank you Dave for sharing your thoughts. Use AMSOIL 25,000-Mile Ea Oil Filter (EAO11) to take advantage of the extended drain capabilities of the oil. Replied by Tech Admin
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ONLY Amsoil!
I've taken several engines apart but only engines that have run Amsoil and they only need coolant system work. Conventional oil precipitates out garbage and sludges up engines resulting in CLOGGED oil passages. If your switching from conventional, get the best protection you can get that has tons of positive history. Do your homework/research to understand ALL the costs involved. You will determine Amsoil is the best switch you can make for your vehicles.