A Technical Understanding of the Gen5 Oil Level

[Jack B]

This forum has been bombarded with a range of opinions and comments about reading the oil level.I had some time last winter and decided to try a more technical approach and took some simple measurements.


Caveats and ground rules:
This is one car and one of the early dipsticks

Do not shoot the messenger, this is a simple forensic case, merely an engineer interpreting some simple measurements.

This is not a thread where we want posts such as - “I was told”, please only hard verifiable input.

Please add to this thread if there is repeatable proof of the additions.

Please make corrections to my calculations or assumptions if errors are noted.

Some of us take an affront when one questions their ability to read a simple dipstick, this is different, every one of us has read his car’s oil level incorrectly, it is the smearing affect that causes these incorrect reads.


Procedure:
Check Oil level at 5 minutes, 30 minutes and 24 hours after the engine is shut down.

Measure the oil level above bottom of the oil pan.

Measure oil pan capacity/volume.


Test Mule:
2013 Gen Viper running 10-40W Royal Purple HPS with less than 50 miles run time on the oil. Oil levels were taken at 60F.


Miscellaneous:
This review took approximately 100 dipstick/oil level readings with high magnification optics. In addition, 25 macro pictures were taken.


Oil System Capacities:
In general, engine oil volume/qt is 58 cubic inches per qt (10 qts = 580 cubic inches). This equates to 193 cubic inches of oil per 1” in oil height. In other words, the average oil level increases 0.3” (approx. 9/32”) for each quart of oil added. The key here is average, the cross-sectional area of the pan is larger near the top, therefore, the change in oil level is closer 0.2” (approx 6/32”) per qt that is added when you are near the top of the safe range. An assumption was made that the oil pan held 10 qt and the other qt was in the engine and filter. I am going to measure the amount of oil that comes out of the pan in my next oil change.

The dipstick’s (2013) cross hatched range (safe area) is ½ in length or 16/32”.

With 10 qts in the pan, the oil level is 3” above the bottom of the oil pan.

The cross sectional (average) area of the oil pan interior is approximately 200 square inches. The pan is approximately 4” in height.


Oil Level Measurement:
Problems: Keep in mind this is a test on one car. Most of what follows probably would not be detected for an eye-only level check, I had the advantage of using a close-up macro lens.

The dipstick has a spiral at the top and the bottom, I believe the bottom spiral actually picks up more oil than a non-twisted dipstick and deposits it in the tube, this in turn smears the oil in the graduated area of the dipstick. In effect, the more you check the level, the more the smear hides the true reading. This is also why you get a good reading long after a shut down, such as one week later. This is because the surface oil in the tube is gone, therefore, no smear. I did remove the twist; it did not help a lot.

These measurements were taken with new oil, it might be easier to read the dipstick with older oil. However, Royal Purple has a tint out of the bottle.

I always thought the dipstick entered the oil pan at an angle, I was wrong, it enters almost perendicular. Therefore, in a perfect world both sides should read the same.

For some reason the side (on my car) of the dipstick surface facing the rear of the engine grabs more excess oil and smears/overwrites the true reading. This is not obvious with the eye alone. In my testing I tried to take the readings with the graduated side of the stick facing the front. In general, the side of the dipstick facing to the rear appears to read higher than the front side, however, that is deceptive due to the smearing affect.


The Readings:
To establish the change on the dipstick per quart of oil, I added 2 qt of oil when the dipstick level was a little under the top of the graduated area. Basically, that raised the level by 12/32”, or 3/8”, therefore, each quart added increases the level by 3/16”, again, this is in the graduated area. This also means the graduate/safe area of the dipstick is approx 2.25 qt.

Here is the hard one to accept, after dozens of engine on/off cycles and over a hundred measurements, it appears there is very little difference in the level after five minutes, one hour and one day. The level seems to change between 1/32” and 2/32” total in those time periods. I was using magnification, plus, if you add the smear factor to the equation, I do not see how you can consistently obtain a true reading. Again, one car and one dipstick, someone may have a car the reads differently, however, from the number of oil related posts, it seems a lot of cars are similar to my car.

Simply put, there is not much oil that drains into the pan after the engine is shut off. The max that drains back into the pan is 1/3 of a qt, but, probably less. This is 2/32” on the dipstick, basically imperceptible on these dipsticks. After several days the oil in the dipstick tube drains or dries, then the oil level becomes easier to read.


Caveat – do not do this: I checked the oil with the car running, the oil level does not change much from the engine-off state, this supports the comments in the above paragraph.


Conclusion
the Gen 5 viper dip stick is hard to read due to the smear created by oil transferred from the dipstick to the tube and then back to the dipstick. After long periods of time (one week of longer) the tube loses the oil and the first oil check is more visible. It appears that checking the oil at 5 minutes, 30 minutes or 24 hours makes very little difference. The safe/graduated part of the dipstick is approx 2.25 qt.


The above information is not intended to alter the oil verifying process required by the manufacturer, the data is extracted from one car and should not be considered as basis for any oil related tasks or routines.


Example: Below is a 2013 GEN5 dipstick:
The left arrow is the top of the smear.

Look close at the dipstick, the top right arrow is the actual oil level. The photo does not clearly show the level, however, when viewing through the camera/macro lens, the level does show up.

The back side of the dipstick is not smeared and shows a level close to the right arrow. However, the level is not obvious without the macro lens.

2913 Dipstick 12 HR 24 IMG_2335.jpg

[ViperJon]

This is great info and precisely the conclusion I have found as well. There is very little variation between five minutes after and 24 hours after. Despite what some have consistently insisted is up to a 1/2” variation it’s just not true they are reading it wrong. Personally I change my own oil and let my old oil drain for hours or overnight. Every drop. Then add the 11 quarts and have an exact benchmark of where 11 quarts should be warm or cold it doesn’t matter. I’ve found its about an 1/8” variation. I always check it cold as it’s easier to read.

[sharmut]

Jack, this echos my readings over the years on the 2014 TA. There was never a noticeable difference between reading the oil level after 7 mins of motor runtime versus overnight. I was always under the impression, the overnight reading would display higher levels when the oil is allowed to drain into the pan.

[ViperGeorge]

I can say that there does appear to be some variation between cars. My 14 GTS and my 17 ACR read about the same regardless of how much time the car sits after shutdown. There is some variation but maybe only due to smear. As Jack says these dipsticks are dipshit.

My old 15 TA 2.0 varied dramatically from 5 minutes to 24 hours. I don't know why this was. After having the dealer change the oil in the TA I checked it the next morning with the engine cold and it read substantially higher than the hash mark. I thought the dealer had added way too much oil. I can't attribute it to tube wipe since the car sat overnight and the line on the stick was clean and straight. After running the car and letting it sit 5 minutes the level was dead on the top of the hash mark.

Changing the oil myself the next time it was due resulted in the same readings. I took pictures of the dipstick but I'll be damned if I can find them. I will look again. I cannot say why the readings in the 15 were so different from 5 minutes to 24 hours but I hope you believe me that they were.

Jack, can you think of any reason why the readings would vary so much on my old TA? Also why would the manufacturer specify to check the oil after engine shutdown given your findings? I have previously posted an email from the engineer that worked on the engine oiling system so I know he believes it is better to check after 5 minutes but given your data I don't know why. It would seem that checking it when cold would result in an easier reading since tube wipe would be less of an issue.

I will have to do some experimenting on each of my cars to see how the readings vary.

[Voice of Reason]

I love this thread so much and hopefully this puts an end to the debate.

[AZTVR]

Is there absolutely only one way that oil cooler lines can be oriented? Would differences in orientation change leakdown rate? One way to find the cause of an issue is to determine how actual reported observations could be true rather than dismissing them out of hand as mistaken. I think that is what Jack is attempting to do by applying some scientific and engineering principles. What I have found in years of investigating failures, is that you can discover causes that you would never ever have thought were possible.

[ViperGeorge]

Is there absolutely only one way that oil cooler lines can be oriented? Would differences in orientation change leakdown rate? One way to find the cause of an issue is to determine how actual reported observations could be true rather than dismissing them out of hand as mistaken. I think that is what Jack is attempting to do by applying some scientific and engineering principles. What I have found in years of investigating failures, is that you can discover causes that you would never ever have thought were possible.

That is an interesting question. My 15 TA 2 had aftermarket oil lines as does my 17 ACR. However I suppose it is possible that when the tech installed the lines on the 15 he oriented them in some way that allowed the cooler to drain. Don't know and I don't have the car anymore to check.

[texasram]

The left arrow is what i was always referencing

[TA Two Oh]

Great thread... thanks, Jack for taking the time to cook up this experiment, do the readings and apply your vast knowledge to them. I have nothing to add other than that my experience parallels yours. If there's a difference between my 5 minute and 24 hour readings, it's imperceptible to my eye.

[Evil v10]

This thread has a lot of info,once again thank you.

[SRT_BluByU]

I dont believe this to be accurate for all gen v’s. My 2017 (TA/GTC) has a 1 quart crosshatched safe zone. Also, i checked yesterday and early morning stone cold reading v. 5 min after a warm up drive had a difference of 1/2 quart.

Ill keep checking my oil the way the user manual recommends (5 min after warm engine shut down). Ymmv.

[ViperGeorge]

Not to stir the pot but... My 2017 ACR has been sitting for almost 2 weeks unstarted so I thought I would check the oil level cold. It was 1/2" to maybe 3/4" OVER the top of the "SAFE" hash mark. I tried to take photos, they are a bit blurry but hopefully they are clear enough. I couldn't figure out how to use the Macro function on my lens although I think it has one. I pulled the dipstick and looked at the level. I also wiped it off and re-inserted it and read it again. It was the same both times, well above SAFE.

The first photo is of the oil level (yes the oil needs changing). The arrow points to the oil level. The second photo shows the safe zone after I wiped off the oil. I couldn't see the SAFE zone because the oil is dirty so I had to wipe the oil off. One arrow shows where the original oil level was and the other shows the SAFE zone. I assure you these photos are un-retouched. The car is a 9 liter and has the Viper Specialty oil lines as did my old 15 TA 2.0. The oil lines were added when the 9 liter was installed aa few months back. There was exactly 11 quarts of oil added to the car when last changed and the 9 liter being new does tend to burn some oil. The oil has a few track days on it.

IMG_4263 (2).jpg
IMG_4264 (3).jpg

[Jack B]

Not sure what you are saying, give us a one-liner.

Not to stir the pot but... My 2017 ACR has been sitting for almost 2 weeks unstarted so I thought I would check the oil level cold. It was 1/2" to maybe 3/4" OVER the top of the "SAFE" hash mark. I tried to take photos, they are a bit blurry but hopefully they are clear enough. I couldn't figure out how to use the Macro function on my lens although I think it has one. I pulled the dipstick and looked at the level. I also wiped it off and re-inserted it and read it again. It was the same both times, well above SAFE.

The first photo is of the oil level (yes the oil needs changing). The arrow points to the oil level. The second photo shows the safe zone after I wiped off the oil. I couldn't see the SAFE zone because the oil is dirty so I had to wipe the oil off. One arrow shows where the original oil level was and the other shows the SAFE zone. I assure you these photos are un-retouched. The car is a 9 liter and has the Viper Specialty oil lines as did my old 15 TA 2.0. The oil lines were added when the 9 liter was installed aa few months back. There was exactly 11 quarts of oil added to the car when last changed and the 9 liter being new does tend to burn some oil. The oil has a few track days on it.

IMG_4263 (2).jpg
IMG_4264 (3).jpg

[Jack B]

If it is a 1/2" zone, it is 2.25 qt.

I dont believe this to be accurate for all gen v’s. My 2017 (TA/GTC) has a 1 quart crosshatched safe zone. Also, i checked yesterday and early morning stone cold reading v. 5 min after a warm up drive had a difference of 1/2 quart.

Ill keep checking my oil the way the user manual recommends (5 min after warm engine shut down). Ymmv.

[ViperGeorge]

Not sure what you are saying, give us a one-liner.

Checking my ACR oil level cold results in an level that is 1/2" to maybe 3/4" inch higher on the dipstick than if checked 5 minutes after running. If your calculations are correct then my cold oil level is maybe 2 quarts higher than checking per Manufacturer recommendation.

[StrokerAce]

Good info. My 13 when measured at various times after running has shown minimal changes on the dipstick. That being said it's maybe 1/8th of an inch variation.

[Evil v10]

Early gen 5 Viper have dip stick with different safe range than on updated dip stick

[SRT_BluByU]

If it is a 1/2" zone, it is 2.25 qt.

Hi Jack. If ya read my post thats why i mentioned it is not accurate for all gen v’s. My safe zone is not 1/2” and is a 1 qt. safe zone. Id hate to see someone the later years gen v think its a two[ quart safe zone and overfill. I dint know the cutoff.. but earlier gen v’s have different dipsticks than later gen v’s. Also cold v. 5 min after warm engine shut down difference is about a 1/2 qt. On my 2017.

I think the 5 min after warm shut down keeps things consistent as its a known temp all cars will have and be the same.. where as cold reading temperatures can vary widely! Im gonna keep checking it as the user manual recommends

- - - Updated - - -

Early gen 5 Viper have dip stick with different safe range than on updated dip stick

Correct

[ViperGeorge]

Early gen 5 Viper have dip stick with different safe range than on updated dip stick

If the yellow ring on the top of the diipstick is parallel to the windshield you have the newer style. If the ring sits at an angle to the windshield you have the older style.

[Evil v10]

The updated dip stick is still available to buy and install for gen 5 .

[Jack B]

The diff between hot and cold oil is not discernible from a volume standpoint in the viper pan configuration. As I stated in my post, if you check the oil cold, then start the car, the oil level while running does nto change much.

Get a non-phone camera and take some macro pics and repost your pics. take a pic of both sides.

Checking my ACR oil level cold results in an level that is 1/2" to maybe 3/4" inch higher on the dipstick than if checked 5 minutes after running. If your calculations are correct then my cold oil level is maybe 2 quarts higher than checking per Manufacturer recommendation.

[Jack B]

The updated dip stick is still available to buy and install for gen 5 .

I will buy a new stick this week and make a comparison

[ViperGeorge]

The diff between hot and cold oil is not discernible from a volume standpoint in the viper pan configuration. As I stated in my post, if you check the oil cold, then start the car, the oil level while running does nto change much.

Get a non-phone camera and take some macro pics and repost your pics. take a pic of both sides.

Jack, the photos were taken with a Canon 80D with an 18-200mm Canon lens. I had to shrink the file size to post them.

[SRT_BluByU]

Jack - the difference is between cold level measurement and 5 min after engine shutdown after its reached normal operating temperature. I did this test myself Saturday and it yielded a 1/2 qt difference in level.


5 minutes after cold shutdown is not the same...

[ViperGeorge]

The diff between hot and cold oil is not discernible from a volume standpoint in the viper pan configuration. As I stated in my post, if you check the oil cold, then start the car, the oil level while running does nto change much.

Get a non-phone camera and take some macro pics and repost your pics. take a pic of both sides.

Jack, then how do you explain the difference in cold vs. 5 minute shutdown readings that some of us experience? Even though my pictures weren't super clear the arrows show you where the oil level and safe zone were. As I said about 1/2" to 3/4" difference. To me that is pretty huge. What else could be going on?