Castrol GTX Cold Weather Performance

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Does anybody who live in colder climates notice any negatives with using GTX in a 5w20 required engine? I've been thoroughly researching different conventional oils and notice that GTX seems to be on the thicker side of the 5w20 spectrum which could be a good thing. I was just wondering about cold starts and operation in very cold weather.

It doesn't get far below zero but there are stetches of single digit weather and occasionaly in extreme cases maybe slightly below zero.

I've always liked GTX and used it in my non-Ford vehicles over the years but never anything requiring 5w20.
 
Nothing against the GTX but i see you are using Motorcraft in your Ford so why not use there very good 5w20? It has a very good rep on this site.
 
I've wondered the exact same thing.

Castrol publishes 'max specs', not the actual tested values of the oils, so no-one knows how they stack up against other oils.

On the other hand, 5W-20 is a pretty thin oil overall, and I've never actually heard anyone ever claim they had anything other than effortless winter starting with a 5W-20.
 
With the new car I want to go with an oil meeting the exact specs of Chrysler. The Motorcraft doesn't explicitly state that it meets MS-6395 and I'm paranoid so I'm going to go with my second favorite choice. Lol
 
Originally Posted By: Inline200
With the new car I want to go with an oil meeting the exact specs of Chrysler. The Motorcraft doesn't explicitly state that it meets MS-6395 and I'm paranoid so I'm going to go with my second favorite choice. Lol


Kendall High Performance Synthetic blend, meets all of Chryslers specs as well as Ford's and is made by Conocophillips the same as Motorcraft Synblend. Very good oil, with added wear protection with the "liquid titanium". Also has excellent cold weather pump-ability.
 
That's what I've read here but why would Chrysler specifically state that the oil must be API certified and also meet MS-6395?

That is confusing me.
 
I have never used 5W20 but I did use 5W30 GTX exclusivly in a couple vehicles for a couple years. Our weather here is about the same as yours I think and I never noticed any problems. Funny enough, that is the same reason I picked GTX, was the only conventional at the time that listed GM6094M on the back of the bottle. If it meets the specs, it shouldn't be a problem but ya, more specs from BP would be nice.

Honestly, a lot of us over think all of this. I bought the syn hyp for a bit but I've decided to go back to conventional. Some really good used oil analysis at factory intervals. I'd be going back to GTX if Formula Shell wasn't $10/case cheaper at Costco and still might if for some reason I don't like the FS.
 
For what it's worth.. I'm at walmart and gtx doesn't explicitly state that it meets the Chrysler spec either. Pennzoil Conventional and valvoline conventional do though.
 
That's strange. I just saw a bottle the other day with the spec. listed and the most recent PDS online with GF-5 lists it as well.
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Well just use Pennzoil Conventional or Valvoline conventional. Problem solved. If you can't get the GTX out of your head, use it. It will be fine. If you're worried about the spec, use an oil that specifically states it.
 
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Actually we don't know how light or thick the GTX 5W-20 is compared to other 5w20 conventional oils because Castrol doesn't provide the HTHSV spec'. The KV100 spec' of 9.1cSt is high but that could be due to a high percentage of VIIs and it does have a relatively high VI of 158 for a 5w20 conventional.
As far as I know all 5w20 conventionals have a HTHSV in the 2.6cP area, and that is likely what it is for GTX. That being the case, with it's 158 VI it's likely lighter on start-up than most 5w20 conventionals.
 
Originally Posted By: Inline200
That's strange. I just saw a bottle the other day with the spec. listed and the most recent PDS online with GF-5 lists it as well.


As others have pointed out, BP doesn't put a lot of helpful, actual test results into their product data sheets. Oh well, such is life.

I don't have anything that uses 5w-20, but I, like cp3, chose the GTX 5w30 because it explicitly stated the GM specification and I was servicing a GM truck in fleet usage. It was on sale, which didn't hurt, either.

If it meets the specifications you require, and you state that it does, use it with confidence. It doesn't seem to be the darling here on BITOG, and for whatever reason, it's not my favorite either. That hasn't stopped me from using it many times, though, particularly when the price was right. My old LTD got GTX for about half of its 500,000 km lifespan, for what it's worth. And it spent its entire life outside, starting many cold, -40 mornings with GTX 5w30 in it.

Most here who don't like it do so because of the price, I suspect. In Canada, though, at least here, it tends to be the cheapest big name conventional.
 
During the 60's, 70's and even part of the 80's, we drove rear wheel drive American Iron with their slow cranking starters and using 10W40 type oils during the winter and the engines always started. We experienced some of the coldest, snowiest winter in our history even reaching into the sub zero temps. Battery trouble and slow catching carburators was more frequent as I remember but, once past those issues, the engine was starting/running!

Today with better engine tech/design and EFI along with using required oils(5W20 or 30) there should be few issues starting especially in NYS. Yes, certain part of NYS experience the sub zero temps regularly in the winter.

I have never tried to start an engine at -40 deg C or F(same temp) but I have started an enging at -15 deg F. A little slow but it fired. I have felt < -40 deg's as the lab where I work, Ultra Low walk-in freezers where serum is stored is set at -50 deg C and PPE and the buddy system is requires prior to entering.

These freezers would be the perfect storage place to test the different qts of oil for their Pour Ability after setting for a couple of days but, I don't think that the MGT nor the FDA would appreciate it very much(how would they know?). Don't think that I haven't entertained the thought
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but, I'm retiring soon and wouldn't want to jeopardize my position.
 
Like others here, I love all things motor oil. I love changing my own oil. I love oil filters. However, I think this whole "must use manufacturer spec'ed oil" thing is a little overblown.

You want to use Castrol GTX? Go ahead. If you use the proper weight (which I'm assuming is 5w-20), use a quality oil filter, and change it according to the owner's manual, the engine (and you) will be just fine.

I believe that, in the grand scheme of things, using the proper weight oil and following the proper OCI are both much more important than having that manufacturer spec being listed on the back of the bottle. Sure, there will always be that ONE exception; but, for 99% of the cars on the road, it will follow that general order of importance.

As far as worrying about a 5w-20 being to thick for winter weather? Come on! It wasn't all that many years ago when people were freaking out because 5w-20 was "like water", and it would ruin engines because it was SOOOO thin. Now we're woryying about if it's too thick?! Come on, guys. Let's worry about other things.

Just my .02 I'm not trying to offend, and maybe I've mellowed too much over the years. Not withstanding, as long as you use any of the big boys (i.e., Pennzoil, Castrol, Valvoline, Motorcraft, Kendall, Mobil, etc.), you and your car will be just fine.
 
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