I Have a 2006 Hyundai Sonata With the 4 Cyl. Engine and all i run is Castrol Products Like
Castrol GTX 5W-20. It's the best oil for the price.

I'm using it...and had no problem...the engine feel smooth and light...even when it come to due for service...

I bought a 1994 Chevy Silverado C-1500 with the 5.7L V8.Next day I changed the oil to Castrol Edge 10W-30.All I got to say is OMG! The Tach went from 900 idle to 250 And after two months still doing this!.Oil pressure lower at idle than conventional oil.water temp went from 195 to 145 in heat of day!,runs real smooth and no startup issues.cruise all day idle all day,no problemo. Ill never use anything else. No formal testing I just looked at the gauges before and after you chhange the oil.You got to see to believe If you not using Castro;Edge you need to whip yourself with that dipstick and save that Irishmam the trouble.This oil is off the chain!!

I used Mobil 1,recently switched to Castrol Edge on my 1997 HONDA CIVIC DX. Feels like I put in a brand new engine. So smooth, quiter and best gas milage ever. The almost ran few hundred miles but still it's look the same like first day BRAND NEW OIL.
BTW when I was using Mobil 1, my oil pan gasket started leaking and had to change it.

USE CASTROL EDGE or DO NOT USE ANY OTHER CRAPPY OIL

If you want to keep your vechile and want to drive it for a long time !!

Just try once you will notice what I am talking about

Salute to Castrol EDGE, best oil ever made !! That's it

Castrol syntec is the best stuff I have ever used for the price. It may not be real synthetic oil but its used in older car. The Castrol Edge is even better and its a real synthetic but for price premium and it competes with Mobil1 now and claims 15000 mile oil changes but I stick with 5000. It is now a real synthetic type 4 PAO.

GTX High Mileage oil is good for making older engines run nice and smooth, however their "superior oil burn off protection" is subpar IMHO. vehicle (91 honda civic) burns more with this oil than it did with Valvoline oil of same viscosity. Still good oil though.

I might be biased since I help promote for Castrol, but unlike regular synthetic oils like Mobil 1 and Castrol SYNTEC, Castrol EDGE offers extended drain interval protection, provides unsurpassed wear protection*, and meets the world’s toughest industry-agreed standards. Because of this combination of benefits we put it in a higher class of oil called “advanced” synthetics.
*5W-30s tested in industry standard sequence IVA wear test

Best oil Enough said.

Castrol is the best oil, but it is also the most expensive. I like it, but not enough to pay its price. I use Havoline when I change oil.

I have 2 1980 model Toyotas 4x4's that have over 200000 Miles and all that has ever been in them GTX.

Best oil you can run in ure truck.

I have used the Castrol synthetic blend motorcycle oil in my yamaha and found it to be a good all-around oil. Pretty good value in the motorcycle oil category too.

Castrol Syntec... One of the best oils out there! It loves a good beating! Keeps your engine clean and gives it better performance! Very long lasting oil if you ask me! I love the stuff!

I just put the GTX conventional oil in my boyfriends car. The oil has a ver clear/clean look to it. So far so good.

I used to use penzoil religoisly like my dad and my grandpa before me, I got rebelious and tried a few other oils but when i tried castrol syntec 10-30 it felt like someone droped a brand new engine in my old truck and i was converted

It is a good oil. Nothing more can be said.

Best for petroleum oil and best for the price. Mobil 1 is the best synthetic for the money.

i used to use quaker state. when i switched to castrol gtx, the metal shavings on my car's magnetic drain plug virtually disappeared. with quaker state, they were larger and there were more of them.

Used Castrol GTX 10W-30 in our car and lawnmower before and seems to be just fine but I havent't used it enough to have made up my mind to keep on using in my car regularly. 1 thing I did find odd tho is I had a 4.4L jug of GTX 10w-30 the oil appeared to be blue which is i assume their way of doing it then after I had the jug sit a while before I needed oil for the lawnmowers it was the regular colour brown/golden like most all oils. I dunno if maybe it was the light that day outside or what but I'm pretty sure thats what I saw. But in any case it seems to be good. And it is true they do put an awful lot of money into Ads and making fancy looking jugs...so I wonder. Best way to know is try it yourself or check out the data sheet specs. But I personally have now switched to Valvoline for a while. [Biggest thing is O&F-5kmOr3m]

Have never used better oil, except for synthetic.

Castrol's 'Syntec' synthetic oil is excellent. I drive a VW and the manual advises 10K oil change intervals with synthetic oil. I've done that many times with the Castrol Syntec, and my car has not had any issues with the motor.

Never had any luck-breaks down easy.

i ve never had any luck with this oil it breaks down too fast looses its color very easily.

This oil is crap. They put more money into advertising than into making their product. Mobile 1 is the best oil around and is made by esso. I have ran mobile in my car. It now has 700,000 on it and is still running

This oil is crap. They put more money into advertising than into making their product. Mobile 1 is the best oil around and is made by esso. I have ran mobile in my car. It now has 700,000 on it and is still running

All of their oils are absolutlely great. The GTX which I have used,just the plain cinventional,is this best that i have ever used for conventionals and the syntec has given me the best dyno results for my trans am ever, anything that Castrol makes is probably the best and most practacle.

Can't beat

I think That this is the best oil for the price. I use it in my 4 cylinder truck( Extreme heat) (extreme cold) Never have noticed any problems. CASTROL GTX AND CASTROL High Mileage are The only oils I put in my truck.

I always used Castrol in my car, the Syntec blend is an excellent oil.

I have heard from refinery engineer that most all the brands use the same feedstock and then blend their own additives and most of the differences are miniscule at best!!! the synthetics are only manufactured by ONE company refinery [Mobile] then additives blended.

I change oil all day long at The Duke Of Oil in Palatine,Illinois, this is the best conventional oil out there. the best syn. oil is amsoil,2nd best is mobil 1.

THis only applies to the full synthetic though. 3500miles and the oil is still quite clear