Shell RGT question

[wbwanzer]

I enjoy reading this forum, but am no where near in the same league as most of you folks concerning oil knowledge. So, here is my situation. Vehicle is a 2019 Kia Sorento 3.3 V6 with 3000 miles now. So engine is still breaking in. For the past month I was getting between 22.2 and 23.5 mpg average filling up each time and using Fuelly to calculate and keep track. All of my driving is the same. Short trips around home and once a week highway trip of 120 miles round trip to Baltimore and back.

I did my first oil change last week with 2700 miles on the odometer. I put in Shell RGT in 5w30 as prescribed. It has only been a week, but my mileage seems to be down noticeably. I first noticed it on the in-car info screen which keeps track of mileage for that trip. The numbers were down. Then when I filled up last, the calculated mileage was 21.7, with the same driving scenarios. No excessive idling or city driving. Same driving routine as usual. So the question is, is RGT on the thicker side? I assume that original fill was Total Quartz. Don't know much about that.

I'll continue to monitor but my early impression is that the RGT is considerably thicker than whatever was in there originally.
I know that I'm not driving a truck and I don't tow or haul, but the RGT says that it is suitable for use in all gasoline engines so I thought I would give it a try.

Thanks for any help.

 

[domer10]

That's weird, I noticed a increase. But I also always run non ethanol gas, and use a small dose of archoil, but I still noticed a pretty substantial increase with 5w30 going from Mobil to RGT with same set of variables.

 

[blufeb95]

5w30 should be between 9.3 to 12.5 cSt at operating temp, RGT is 11.7, so it is on the thicker side for a 5w30.

 

[Virtus_Probi]

Looks like 5W20 is recommended for this model and engine.
You might just be seeing the difference between 5W20 and 5W30 at normal operating temps.

 

[HappyLittlePony]

Not enough data to come to any sort of conclusion. It's just as likely that you got a tank of "bad gas" or something.

For that matter, does anyone know what is the factory fill on a Kia Sorrento? They might have used a 5w-20 or 0w-20 as "break in" oil.

 

[blufeb95]

Originally Posted by Virtus_Probi
Looks like 5W20 is recommended for this model and engine.
You might just be seeing the difference between 5W20 and 5W30 at normal operating temps.

The manual says to use xW30 weight only for the 3.3L V6

 

[ragtoplvr]

Now API has discontinued the energy conserving grade test and the starburst, it is harder to choose. Thank API

Rod

 

[dippschtick]

Agreeing with blufeb on this. Try Pennzoil Platinum next time.

 

[kschachn]

It's not clear from your post but are you saying you used the same oil grade each time? There is absolutely no way you could attribute a mileage change due to two oils of the same grade. Considering the myriad of uncontrolled variables in everyday driving such a minute difference is deep in the noise.

Even between two grades it is not possible. I linked an article once that discussed measuring real-world fuel economy and they discussed that in order to get any sort of accurate data, specialized test fuel must be used because normal gasoline had about a 4% energy density variation even at the same station. There are many other uncontrolled variables that also contribute to fuel economy changes.

Observing a change is one thing but being able to attribute it to one isolated variable is a far different task.

 

[Virtus_Probi]

Originally Posted by blufeb95
Originally Posted by Virtus_Probi
Looks like 5W20 is recommended for this model and engine.
You might just be seeing the difference between 5W20 and 5W30 at normal operating temps.

The manual says to use xW30 weight only for the 3.3L V6

My bad, I found a site that claimed 5W20 for the 4 and 6 and now see that was a dubious site.
Now I find another site where a guy swears that it calls for 0W30 on his fill cap!!!

 

[wbwanzer]

Originally Posted by kschachn
It's not clear from your post but are you saying you used the same oil grade each time? There is absolutely no way you could attribute a mileage change due to two oils of the same grade. Considering the myriad of uncontrolled variables in everyday driving such a minute difference is deep in the noise.


I have only changed the oil once. Last week. I am assuming that the factory fill was 5w30 or at least xW-30 since the owner's manual does not show any xW-20. The filler cap says 5w30. So that is what I put in.

The manual calls for 6.87 quarts to refill with filter. I put in 7. I can't imaging that .13 of a quart is too much extra oil.

 

[Virtus_Probi]

Originally Posted by wbwanzer
Originally Posted by kschachn
It's not clear from your post but are you saying you used the same oil grade each time? There is absolutely no way you could attribute a mileage change due to two oils of the same grade. Considering the myriad of uncontrolled variables in everyday driving such a minute difference is deep in the noise.

I have only changed the oil once. Last week. I am assuming that the factory fill was 5w30 or at least xW-30 since the owner's manual does not show any xW-20. The filler cap says 5w30. So that is what I put in.
The manual calls for 6.87 quarts to refill with filter. I put in 7. I can't imaging that .13 of a quart is too much extra oil.

How does the oil level look on the dipstick...assuming you have a dipstick?

 

[wbwanzer]

Originally Posted by Virtus_Probi

How does the oil level look on the dipstick...assuming you have a dipstick?


There are two dimples on the dipstick. A lower one and a top one for 'full'. Oil level is at the top dimple.

 

[wbwanzer]

As I said in the original post, I'll keep an eye on it, for sure. I generally get gas about once a week, although not driving much this week.

I know that this was a one fill-up test interval, but the daily driving numbers were down and the calculation after fill-up was down.

 

[ka9mnx]

Engine is still breaking in. Fuel economy can be all over the place.

 

[Virtus_Probi]

Originally Posted by wbwanzer
Originally Posted by Virtus_Probi

How does the oil level look on the dipstick...assuming you have a dipstick?

There are two dimples on the dipstick. A lower one and a top one for 'full'. Oil level is at the top dimple.

Sounds perfect! You should be golden there.
The only other meaningful variables I can think of are using E0 gas before the oil change and E10 after or maybe getting stuck in horrible traffic on your last Baltimore trip.
Well, there is also weather...I usually get 25-26mpg driving up to our ski place in the winter and noticed the mileage drop down to less than 21mpg one night when I was driving into the teeth of a howling North wind. My car was buffeting around the whole drive and it was exhausting!

 

[UNC197]

Did you use the same gas station? Most likely a slight variation in gasoline.

 

[wbwanzer]

Originally Posted by CharlieJ
Did you use the same gas station? Most likely a slight variation in gasoline.


I use two stations. Sunoco or Exxon, depending on where I am.

 

[Duffyjr]

How about the weather, has it been colder since the oil change.

 

[wbwanzer]

Originally Posted by Duffyjr
How about the weather, has it been colder since the oil change.


Not really. Mostly been forties and fifties the last few weeks.