Any GTX users?

Status
Not open for further replies.

SR5

Joined
Jul 7, 2015
Messages
6,707
Location
Down Under
The first oil I ever used was Castrol GTX 20W-50, back in the day. With time I moved on to bigger and better things, Penrite oils, full synthetic oils, etc.

Being a belts and braces sort of guy I have been using a lot of full synthetics (Castrol Edge, Shell Helix Ultra, Valvoline SynPower) with name brand semi-synthetics as my base level oil for some applications.

Anyway last week I went back to basics and put some Castrol GTX in my car. The owners manual specs a 15W-40 A3/B3, so that is what I used, GTX 15W-40 API SN ACEA A3/B3. This is the first time I have used GTX for an oil change in about 15 years.

Yesterday, I went for 8 hour drive through the mountains with my son, and the car was running smooth and well. Given the modern specs, this is not the GTX of long ago, but the modern inheritor of the old crown, at an excellent price point.

Lots of talk about PAO and GTL, but going back to GTX was like bumping into an old friend who is happy and doing well.

Is anybody else out there using old school GTX and enjoying it ?
 
GTX is overpriced and overhyped.Since the 70s its been the oil for smaller-higher revving engines... Of course back then Quaker state was having recalls due to anti friction additives being left out,and Pennzoil was sludging engines....and ARCO Graphite was plugging filters....lol
 
I maintain a lot of my family's vehicles. I have Castrol GTX SynBlend running in the 2002 Chevy Trailblazer, and my mom's 2003 Buick Rendezvous. My brother is running it in his 1996 Lexus ES300.

I have no problems with GTX, have used it for quite some time.

To be honest the only reason I'm using it is because I got quite a bit of it on clearance for $1 per quart...
 
It still shows up highly ranked against many premium oils according to several sources including Amsoil graphs and testing as well as many others.

Its better than many would lead you to believe.
 
It's always the cheapest name brand oil here, and I will get GTX 20w50 if I need it and it's on special. I haven't used it in the bike since it went SN, didn't really trust the ZDDP after that, no matter what they said. But for a car, it's which is cheaper, GTX or Penrite?
 
No oil turns blacker quicker than Castrol GTX in my engines. Don't know if that's a good thing or bad thing. Leads me to change sooner because it always freaks me out.
 
GTX 20W50 was the very first oil I ever bought on my own. I used it in my 1987 Olds Trofeo. Sold it with around 350,000 miles. Still ran smooth as silk,used no oil,and leaked no oil. Always gets great uoa's.
 
Mum and Dad's R16 got to 380,000km on it and then some ...odometer stopped working at 380k, so don't know where it went after that.

I used it from time to time, but not currently.
 
It agree on the over-priced comment. It was a very popular oil back in the day here (just watch any old car movie and you'll see GTX memorabilia everywhere.) so I think that mentality has just carried over.
 
It's been a couple of years since I've used it last.
Wouldn't mind using it, if I can ever find it on the cheap.
 
Last edited:
Pretty much all I used for years in 10w30 flavor, year round in everything I owned. Never a problem. I figured if it was good enough for the police department (that is what they used, and still use here) I figured it was good enough for me.

Now I am much more sophisticated (right) but I still wouldn't hesitate to use it especially since they ditched the sodium add pack a few years ago.

I still currently use a lot of Castrol products but tend to buy their blends and full syns these days.
 
I have a bottle of that same GTX 15w40 in my shed, bought a 5.5 litre container of it on sale a few weeks back. Was going to use it in my AU Falcon, but I'm upgrading to a 2006 BF Falcon next week, so I'll save it for that
smile.gif
 
i used to run GTX during the 80s, it was very good oil if not the best of the 20w50's, but have stopped using it since Castrol don't reccomend it for any flat tappet engine since they've reduced the zddp to around 600, i'd rather use VR1 nowadays
 
Originally Posted By: hpb
I have a bottle of that same GTX 15w40 in my shed, bought a 5.5 litre container of it on sale a few weeks back. Was going to use it in my AU Falcon, but I'm upgrading to a 2006 BF Falcon next week, so I'll save it for that
smile.gif



hpb, what oil change interval are you doing with the GTX 15W-40 in your Falcons?

I haven't decided yet. Maybe 12 months and 10,000KM (6000 mi) at the most, but also thinking maybe a bit sooner.
 
Mate, to be honest, the poor old AU is on a "when I can be bothered" basis...last oil change was about 10,000km ago, and I won't be doing another one before I sell it. The BF however, only has 112,000km on the clock, so I'll do a change when I get it home, then again at 120,000km, then every 10,000km from there. I think 10k in your Astra (?) or Vectra (?) is more than acceptable. In their day they probably had 15,000km intervals.

As an aside - the BF recommended oil is 5w30, however the LPG version, and possibly the Turbo's, run a 15w40...now to the best of my knowledge, there is no difference in bearing clearances, etc. between the engines, so I'll use the heavier oil no worries at all.
 
i've run GTX 20w50 in the dead of winter in Finnish Lapland when it was -35c outside ( my car was kept inside a heated garage ) and in 42c heat in Greece, it was a very good oil at the time
 
Originally Posted By: hpb
I think 10k in your Astra (?) or Vectra (?) is more than acceptable. In their day they probably had 15,000km intervals.

As an aside - the BF recommended oil is 5w30, however the LPG version, and possibly the Turbo's, run a 15w40...now to the best of my knowledge, there is no difference in bearing clearances, etc. between the engines, so I'll use the heavier oil no worries at all.


Dead on, it's an Astra (AH) and the owners manual says 15,000km. I would do that (and maybe a little more) with a good synthetic, but with a mineral I think I will stick to 10,000km.

Yeah, if the LPG version of your Falcon can run 15W-40 in pretty much the same engine, it should work fine for petrol. Congratulations on the new car.

Poor old AU. I remember when the AU Falcons first came out. I really liked the Falcon S with the in-line 6 donk, IRS rear end, 5 speed manual, and small rear spoiler.
 
Originally Posted By: Silk
It's always the cheapest name brand oil here, and I will get GTX 20w50 if I need it and it's on special. I haven't used it in the bike since it went SN, didn't really trust the ZDDP after that, no matter what they said. But for a car, it's which is cheaper, GTX or Penrite?


Hi Silk, I fully agree GTX is fine for a regular car, but for a bike only Penrite will do. (When talking mineral oils).
 
Status
Not open for further replies.
Back
Top