Castrol GTX High Mileage

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Apr 9, 2003
Hi everyone, first of I wanted to say that I just discovered this board recently and I am impressed with the wealth of information here. Well, I have a 93 NA Nissan 300zx and it is due for a oil change soon. I decided to use Castrol GTX High Mileage based on the recommendation of many on this forum. Just a few the High Mileage the same formula as regular GTX with the addition of esters and extra thickness? My owner manual states to only use a ENERGY CONSERVING labeled motor oil and the I did not find any such label on the Castrol container. Can anyone explain this? Thanks a lot!
[Welcome!] That's a good question, but without seeing VOAs on each of them, it's hard to say for sure. I'm going to be putting in 5w30 GTX HM in my mom's car this weekend, and will run it until the fall and do a UOA on it. It'll have probably 3-4k on it by then, all mostly short to medium sized trips (although her car warms up very fast, especially in warmer weather)
Originally posted by InfiniteZ: Any thoughts on the Energy Conserving issue?
It probably doesn't get the energy conserving seal simply because it's a thicker oil, so it's going to rob a little bit of MPG. But honestly, it's not going to be a huge amount. Less than 1 MPG difference I would estimate.
For what it's worth, I use Pennzoil HM oil in my van. It's not energy conserving either. It's blended on the higher end of the viscosity range too. I haven't noticed any difference in gas mileage at all. [ April 11, 2003, 09:07 PM: Message edited by: Roger ]
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