Product Reviewed: SAE 5W-30 Signature Series 100% Synthetic Motor Oil (ASL)
Current Rating: 4.97 out of 5 stars
Votes & Reviews: 1010 vote(s) and 1476 user reviews.
Reviewed by Heartbeat of America Bob: 
I use Signature Series 5W-30 in my 2002 Z-28 and my wife's 2002 Cadillac. Meets or exceeds MFG recommendations and has great detergent add packs. Cadillac has 120K miles and no oil related problems.
Reviewed by Dipfedcamaro:
I will be using this oil for the rest of my car is life
Reviewed by mpsmta:
in personal vehicle
Reviewed by Fast lane:
Best Synthetic made!! I use it for 20k in my wife's Subaru. Barely changes color!! Everyone should use this! One oil change a year!!
Reviewed by
Phil:
I switched to Amsoil for my 2017 Escape to see if Amsoils' reputation for quality stands the test of time. I suspect it won't let me down.
Reviewed by Freedom Road:
Great protection, flows great in the cold weather. Nice to change the oil and the filter once a year. Saves time and money not having to change oil and filter several times a year. When draining the oil, the viscosity is the same as it was when it went in.
Reviewed by Thundercat:
Use this oil in my 1993 Corvette. Slightly modified. Have been using this oil since 2010 with no issues, car runs excellent. I believe this product saved my engine when a power wire disconnected from my electric water pump. Engine temp got to 245F (glycol temp) before I shut down the engine. Surely the crank was much warmer than that. Oil was slightly discoloured. Changed oil as precaution but no damage to engine. Just over 126000 miles on engine.
Reviewed by Old school:
I get great results and extended oil life as well as improved fuel mileage with this oil
Reviewed by Storming Norman:
I have Amsoil in everything I own. I've used it for over 20 years. Why would anyone not use Amsoil? I use it in cars,trucks,diesel trucks,motorcycles,lawn mowers and all my hand held lawn equipment. It's the Best protection money can buy for your lubrication needs. I've convinced many of my friends over the years to switch to Amsoil.
Reviewed by James:
I have been using this oil and the recommended filter in my last 4 vehicles. I have changed the oil & filter at 25,000 miles or 1 yr. I have kept the vehicles for at least 200,000 miles and have not had any oil related problems. I drive about 28,000 miles per year.
Reviewed by curt:
7 k on my last change 15% remained ....only oil for my gmc pickup.
Reviewed by David:
wouldn't use any other brand of oil, saves
gas, increases oil pressure,with a longer engine life.
Thank You Amsoil
Reviewed by Dean:
I drive 200/300 miles per day,
Before amsoil I was changing oil every two weeks.now twice a year,
That's awesome,
My last 3 cars have had 200k to 340k.
Not a single oil related issue!
Thanks
Reviewed by Tim:
I'm impressed
Reviewed by Big John:
I've been using Amsoil in all my engines. Am certified ASE Technician. I love the 25k oil and filter. Only have to change my oil once a year. I am money ahead for several reasons 1) cost. 2) time. 3) my engine and seals are in better condition with Amsoil. The molucules are consistent size and fit into tight tolerances.
Reviewed by Mecha-Nick:
Great oil. Used in all of my vehicles. Long drain intervals. Will continue to use!
Reviewed by Ted:
Only change once a year
Reviewed by V2:
High mile toyota vehicles oil and amsoil filters
Reviewed by jake:
20,000 miles on an oil change will get me through for a year so I only have to change my oil once a year. It pays for itself and its less maintenance I have to worry about doing.
Reviewed by Bob:
I'v used this oil for over 25 years.
Reviewed by Ron:
Its what I need. And I will be buying more for the other vehicles
Reviewed by Chris:
My dad has used AmsOil for close to 40 years. I just switched about 6 Months ago. I use it in all of my vehicles including my Work van that i use to pull a 5000lb trailer and is on the road all the time, stop and go!
Reviewed by BUCK:
WE ONLY PUT ABOUT 6K MILES A YEAR ON OUR VEHICLES SO AN ANNUAL OIL CHANGE WORKS FINE AND SAVES LABOR. I HAVE A BYPASS FILTER SETUP (BP90) ON MY TRUCK SO NO WORRIES THERE, UP TO 248K IF MEMORY SERVES.
Reviewed by Jay:
Save me money and gives me peace of mind
Reviewed by W. Slater:
We have cars, trucks, tractors, snowmobiles, atv's, and a Harley,, all have AMSOIL in them and we've never had engine failure. Expensive up front but oil changes are farther apart and you have premium quality product running through the machine and when you look at the long range you have top of the line for the same price as the budget brand yet so much more protection
Reviewed by joe:
This oil and filter and the flush make my high mileage escalade run. It also makes the engine run faster and smoother and it has increased my mileage slightly
Reviewed by BJ:
I use signature series 5W-30 to change my truck's oil
Reviewed by siderwhite:
I use this product for my high mileage Toyota 4Runner and FJ Cruiser to keep them going forever, especially since I'll be retiring soon and won't be able to afford a new car. I change the oil at least every 5,000 miles to keep the engine clean and running strong.
Reviewed by Mongo72:
Just purchased a used truck,tracked the first tank of fuel at 11.4 ,changed all fluids,motor and trans to amsoil . Next reading on fuel came to 15.4 ,significant increase and which tells me that the amoil does what it claims. Will be changing the rear end fluids tomorrow. Stay posted
Reviewed by Chris:
I use in both of my cars that have a gas engine. The oil stays clean for a long time.
Reviewed by dday:
this product has held up to its promise to stand duable to all temps
Reviewed by Craig:
I use in all my vehicles and small engines. 1 year, 25,000 miles or 700 hours. Great product.
Reviewed by Bigred:
This my first time using the oils, and I like it...I would go back to conventional oil.. Thanks AMSOL...
Reviewed by Len:
Always use Amsoil. Best thing or any motor.
Reviewed by Chuck:
Amsoil is the longest best wear protection money can buy. I use it in every machine I own. It has been a product that has never let me down. Thanks Amsoil.
Reviewed by James:
This is used in a 2012 STi. Engine seems to like it.
Reviewed by Jason G:
Use this product in my 2007 G35 Coupe and can say that i definitely can tell a difference in performance.
Reviewed by JZ:
310,000 miles on a Dodge Grand Caravan V6 engine. This is all I need to say, except my previous vehicle was a Geo Metro with 210,000 miles on it. This stuff works.
Reviewed by Brent:
It is a great product, can do 15,000 oil changes (turbo) with 15,000 filter with superior protection at a cost less than a regular oil change. Can't beat that!!
Reviewed by SGR:
Number one in protection and performance.
Reviewed by Dale:
Last longer then average oil
Reviewed by Bern:
To keep all mine and my family cars and truck and motorcycles running at there best
Reviewed by JD Deer Slayer:
I drive a personal vehicle for my job, averaging about 60K miles per year. I started using Amsoil Signature Series over 20 years ago at a friend's suggestion. As soon as I bought the new vehicle, I would drain the existing oil, flush the engine and replace it with Amsoil. EVERY vehicle I have owned since I switched to Amsoil has never had a day of engine trouble, had better gas mileage than predicted, started in the cold Chicago winters like it was summer and blew past 250K miles still purring. I've even had one car manufacturer ask to buy back the engine from me when I was done with the vehicle. I won't put anything but Amsoil in my vehicles. It's just that simple.
Reviewed by Steve:
Great pill always looks good after extended drain intervals!!
Reviewed by Bobby:
I run Amsoil in all our company fleet vehicles, my personal vehicles and all my race bikes. Our one panel van hit 600,000 km and still runs awesome doesn't burn oil and still shifts perfectly, I trust Amsoil for everything.
Reviewed by Northern racer:
I've been using Amsoil for over 30 years. Love it !! I get improved MPG in all the vehicles I use it in . Great stuff , I do six thousand miles between changing. Off sets the price difference.
Reviewed by hikerman124:
I've been using this Signature Series 5w-30 for the 12 years know in the same 1997 Toyota Tacoma 4x4 and it's never ran better. The motor is still like new with 397000 km on it. I do one oil change per year and that it. I'm a probably a slightly more aggressive driver compared to most and this oil is far superior to just about anything that I've come across. I defiantly put it through its paces and its never let me down. I hate to admit this but I even got in an accident once and went to exchange drivers information with the other guy with my truck running and noticed my antifreeze had all drained out from the accident. When I tried to get back into my truck my door wouldn't open even though it was unlocked. For over a half an hour my truck was running with no coolant and no way to shut off my truck. I kept an eye on the temperature gauge the whole time I was trying to get into my truck and the temperature remained in the normal operating temperature the entire time! I thought for sure it was going to cook the engine and I was ready to smash the window open if I seen the engine temperature rising. I finally gained access inside my truck and even drove it home {about 10 km} still without any coolant and the temperature never ever did go up! I give full credit to Amsoil for saving my engine and making a motor oil like no other! That was all about 200,000 km ago.
Reviewed by Diego:
I've used Amsoil
products in my vehicles for many years now. Oil, EA oil filters, EA air filters, Propylene glycol coolant, and several other Amsoil products.
2004 Scion = 200,000+ miles ( purchased new )
2006 Toyota Tacoma = 231,000 miles ( purchased new )
2015 F-150 = 40,000 miles ( purchased new )
None of these vehicles uses oil, or overheats, all are still going strong.
Reviewed by Honda450:
This particular product went in my chevy silverado.Works very well everything you want from your oil only downside is price but you want the best you pay for the best
Reviewed by Footloose:
I have never used the 5W-30 product before, but the vehicle I'm replacing (a 2004 Hyundai with 220,000 miles) never had anything except Signature Series 10W-30. When 'Sam' got totaled, I had
NEVER had to add a quart of oil between changes.
Everything I own that has a motor has Amsoil in it.
Reviewed by Kody:
Amsoil saves me money by providing a product that is guaranteed for 1 year so I only need to do one oil change instead of multiple every year. I use it in everything from my 3500HD pickup to my snowblower and they have provided me with flawless results and I know my engine is being protected for the entire year
Reviewed by Moldy:
It's good oil. Expensive but good. Looks clean after I change it. Can't complain
Reviewed by Kody:
Amsoil saves me money by providing a product that is guaranteed for 1 year so I only need to do one oil change instead of multiple every year. I use it in everything from my 3500HD pickup to my snowblower and they have provided me with flawless results and I know my engine is being protected for the entire year
Reviewed by Fred:
Continuing to use this oil in our 2004 Prius with over 220,000 mi. with no leakage or burning oil between annual oil changes. I've used Amsoil for over 20 years in all kinds of applications always with excellent results.
Reviewed by Big D.:
I have used this oil before, and I'm glad I'm using it again. This oil helps my engine run better, I'm pleased with this oil.
Reviewed by Trevor:
I have used this for several years in all my vehicles. I think it provides the best protection against wear in the engine. Plus in the long run I think it is economical to use, change once a year or 25,000 miles.
Reviewed by The kid:
I am very busy with family , work and play.. so to use this product makes my life a little bit simpler ., I put it in all my vehicles ..so I only have to worry about the oil once a year .. and the protection it gives is also peace of mind .. excellent product. Thank you amsoil .
Reviewed by The Goat:
The engine flush is amazing! I just picked up another gen 1 cummins that has had cheap oil it's whole life....flushed with Amsoil engine flush and wha came out was amazing.....dirty sticky Nast oil clobs....then added the Amsoil 5w30 and installed the oil bypass filter as well and my oil is as clean as it looked when I dumped it in two weeks ago......great products......well pleased.....pricey but very worth it.
Reviewed by Scruffy:
Only use Amsoil in all my engines
Reviewed by Brian:
I have a 2000 Honda CR-V with 240,000 miles on it. The first 40K was conventional oil, then I switched to Amsoil full synthetic. At 240K, it does not use any oil between its annual oil change.
Reviewed by Steve:
I have been using Amsoil products for several years. It is something that you cannot see working but the high milage I have attained on several vehicles while using your product is proof to me that it is good. A few mechanics that I trust have advised me over the years as to what a great product Amsoil is and based on their recommendation and my own knowledge I wouldn't use anything else in my vehicles. Keep up the good work your founding Father started and continued testing / improvement and ease of ordering is always appreciated.
Reviewed by Horseman:
Been exclusively using AMSOIL products in my vehicles since 2005. All three of my gas vehicles continue to run smooth and burn little or no oil.
Reviewed by George:
Love it
Reviewed by Mike:
Switched to amsoil 10 years ago and never going back. Car and truck always run smoother after changes. When I broke a valve spring the mechanic said the inside of the engine was immaculate. And that's with 158,000 miles on it.
Reviewed by
BKT:
I have used the 5W-30 in my F-150 Eco boost since new in 2013. I just hit 100K miles and it runs great, I use it for every day driving and towing a 30 ft. Travel Trailer
Reviewed by Jonesy:
Best oil available anywhere. I am sure it is the reason my 2005 Chevy Avalanche is still going strong with well over 200,000 miles on it!!
Reviewed by Scott:
I used the signature 5w30 in all my cars and trucks. Never a problem. Again...BEST OIL PERIOD!
Reviewed by DeliveryCourier:
Been using this product for more than 3yrs with 25,000 miles oil changes. My Van runs the same as the day I bought it @ 29,000 miles now nearing 248,000 miles.
Reviewed by Torpex:
Bought used 98 Cavalier, changed oil & filter to Amsoil after 3 tanks & ample road tests. Smoother running, increased power and economy. Car pulls hills better, idles better, and shifts smoother.
Reviewed by Gary Kelly:
Use in everything I OWN
Reviewed by Jeff:
I been running Amsoil for years
Reviewed by Nick:
AMSOIL, the best thing that ever happened to my automobiles! I have used AMSOIL for decades and would not change to a different brand even if it came free...
Reviewed by Desert
Dweller:
I've been using Signature Series 5W-30 Synthetic Motor Oil since I purchased my 07 Silverado back in 06. I change my oil once a year and have had no problems at all. My truck now has 196K+ miles and only recently I've had to add about a half quart after 6 months. I think I'll start changing the oil twice a year from now on. My truck deserves it. Amsoil synthetic oils are the best!
Reviewed by Shane:
It dose what it's suppose to do.
Reviewed by Tim1457:
I started using this product in 2011 after talking to an Amsoil dealer at work. He was so confident about the product, I decided to give it a try. I was impressed by the mileage guarantee but mostly how my truck still runs smooth and clean. I have since used the transmission fluid after a flush and fill on my tundra. It shifted so much smoother. Try Amsoil,byou won't regret it. I also use Amsoil in my Honda atv.
Reviewed by KLB:
Very happy with the quality of this oil. Almost no oil use even though my truck has over 160,000 miles
Reviewed by GBDP3:
Use all the time,have use for years only oil I use for my cars.
Reviewed by J.W:
On all my vehicle's, and all my friends and customers. Thank you for it.
Reviewed by J.W:
On all my vehicle's, and all my friends and customers. Thank you for it.
Reviewed by Gabe:
I drive 30,000 miles a year. This saves me a bunch of money on oil changes. Car starts just as easy in winter as it does in the summer.
Reviewed by Mac:
My wife's traverse has only 50,000 miles. I noticed I had to add about a quart of oil between oil changes. I was using Valvoline 5-30 synthetic. After switching to Amsoil I have 8000 miles on this change with no oil consumption. Speaks volumes to me.
Reviewed by MEL:
2018 FORD RAPTOR AND A CAD.
Reviewed by Bandido:
I have an 08 Harley Heritage Softail twin cam with over 52,000 miles on it. One of tbe biggest issues with these motors are the cam chain tensioner, which wear out and can cause catastrophic engine failure. I opened her up at 50,000 and the tensioners look brand new!! Also run Amsoil in my 99 silverado 4×4 throughout ,engine ,trans,transfer case and both differentials this one just turned over 200,000
Reviewed by Timbo:
I have had really great luck and experience in my trucks and cars with Amsoil, they run better have better gas milage and performance, as well as lasting a heck of a lot longer, almost 300,000 miles on my last truck. And the price of the new trucks now a days WOW, so it's Amsoil for this family!!
Reviewed by Anson:
I used to drive a Porsche and the shifting was sticking. i replaced the gear oil with amsoil and it shifted like cutting thru butter.
Reviewed by Kevin:
I drive 100 miles a day to and from work in a 2011 Chevy Cruze ECO 6sp manual and run Amsoil SS 5W-30 and Wix filters, I have sent this oil off for samples and can safely run 18K intervals with a filter change half way between. This oil is wonderful for the engine and turbo.
Reviewed by Azhar Ali :
Opel Insignia 2L Turbo - Petrol
Switching from GM engine oil to Amsoil Signature Series.
What could say this product is beyond my expectation.
Totally can feel the different.
Better engine respond 100 percent.
Cutting down engine noisy
better fuel economy
I should knew this product earlier and no longer back to
to GM oil which is more exp here and no able to match the performance.
Thanks Amsoil
Reviewed by Hallbomb:
This is a great oil. It runs amazing in mu 2008 WRX. Wouldn't use anything else in it.
Reviewed by Wayne:
Run in my mowers great product
Reviewed by Jake:
Works great
Reviewed by FifthPinned778:
This product is just what I was looking for. I didn't think a different brand would make such a difference but Amsoil has definitely hit the the nail on the head with this formula. I run this in my 2006 Subaru WRX Limited and it out-performs Mobil1 and Royal Purple by miles! My rod bearings thank you!
Reviewed by Bill:
Improved gas millage
Reviewed by Slappytm:
Been using the oil for 10yrs on all my vehicles after the recommended break in intervals. Never had any engine problems and love the extended intervals
Reviewed by Berny 655:
Good all around better in the cold less oil changes cheaper on the end less wear.
Reviewed by Puddin:
Excellent service and product
Reviewed by 1stsubie:
My Subaru is nearing 300000 km with the signature series 5W30 since first oil change. Winter cold starts are easy and not engine issue to report.
Reviewed by
Nick:
Title says it all
Reviewed by Granny:
This oil makes a noticeable difference in cold temperature starts. The engine turns over easier leading to
faster starts with less battery draw.
The longer time between oil changes helps, also.
Reviewed by Jdawg:
I strictly only run this Amsoil in all my cars I would never run anything else. I use it in my 1986 Subaru Brat GL, 2002 Subaru WRX, and in my 2009 Toyota Tacoma TRD Sport. I recommend this oil to anyone who only wants the best for their cars or trucks.
Canada
United States
Used oil & filters in my 2002 Tundra since new. Have 175000+
Excellent product. Miles 175000+ change oil & filter once a YEAR