What's The Deal with Dipsticks?

I noticed the 2016 CX-5 2.5 we bought for our daughter has the same issue as the 2019 CX-5 my wife drives...............sorry dipstick design! I'm not stupid. I have been doing my own car maintenance for 55 years and without a doubt these Mazda dipsticks are the worst of any cars I have ever owned. It is too smooth and needs a "crosshatch" design to hold the thin 0w-20 oil in place on the stick. Also, one side will have oil on it but kida smeared and the other side bone dry except on the edges! WTH?WTF? I have NEVER seen anything like this before! It's like the dipstick tube has a wiper on one side. ALSO, I was surprised that the OEM drain plug didn't have a bolt head but used a recessed hex key head instead. That was a first for me. The 2019 has a standard bolt head.
 
Many discussions have been had here on the dipstick. It is indeed hard to read.

Bottom line, you have to let the car sit for a while to get an accurate reading. Then, do a few pulls to get an idea of where the line is, letting your mind see and filter out the variances in extra oil here and there as noise within the signal.
 
Well, Mazda is not the only one with stupid dipsticks.
My new 2023 Kia Stinger has a terrible dipstick. It's not even a dipstick like the old fashioned ones we've had for 100 years. It's like a stiff cable, about 3/16 of an inch in diameter, with a plastic orange tip on it. The markings on are the orange tip, which you can barely read.
Here's the worst part. After a few years of use, the orange tip comes loose, and drops into the oil pan. Yup. the only way to get it out is to drop the pan. Hopefully before it damages the internals. Stupid design.
 
I noticed the 2016 CX-5 2.5 we bought for our daughter has the same issue as the 2019 CX-5 my wife drives...............sorry dipstick design! I'm not stupid. I have been doing my own car maintenance for 55 years and without a doubt these Mazda dipsticks are the worst of any cars I have ever owned. It is too smooth and needs a "crosshatch" design to hold the thin 0w-20 oil in place on the stick. Also, one side will have oil on it but kida smeared and the other side bone dry except on the edges! WTH?WTF? I have NEVER seen anything like this before! It's like the dipstick tube has a wiper on one side. ALSO, I was surprised that the OEM drain plug didn't have a bolt head but used a recessed hex key head instead. That was a first for me. The 2019 has a standard bolt head.
Yeh the oil level dipstick design on CX-5 isn’t the best. But since I always measure the oil level the first thing in the morning before the engine starts like the old days, the oil residue on the dipstick is a lot easier to see, and I don’t even need to wipe the dipstick、insert and pull it to see the oil level. Just one pull and done.

I know many believe we need to measure the oil level when the engine is hot based on the manual, but the manual only says “wait at least 5 minutes for the oil to return to the oil pan”. Yes IMO that could be 5 minutes, or 2 days, after turning the engine off. The manual emphasizes “for the oil to return to the oil pan”, that’s the reason for waiting, nothing about hot oil temperature. In addition, I’d compared the oil level measurements between hot and cold engines, the oil levels showed on the dipstick is almost the same.

Also, when you change the oil, don’t use the 4.8 quarts stated in the manual for your 2.5L NA. Most people use 5 quarts with a 5-quart container. But I always use 5.2 quarts making sure the oil level is at the Full mark of the dipstick after the oil change.
 
Lots of debate about that. :) I believe it should be half-way between MIN and MAX based on the manual, and on every other car I've owned that have 2 spots on the dipstick to determine that the oil is in between the two marks. And when I fill with the specified amount in the manual, it lands...in between the two marks.
 
Lots of debate about that. :) I believe it should be half-way between MIN and MAX based on the manual, and on every other car I've owned that have 2 spots on the dipstick to determine that the oil is in between the two marks. And when I fill with the specified amount in the manual, it lands...in between the two marks.
Your experience definitely is different from mine. For all vehicles I’ve touched, VW、BMW、Honda、Nissan、Toyota、GM、Ford、AMC、you name it, changing the oil for the last 50 years, if I use specified oil quantity in the manual, it all ends up at the Full mark of the dipstick! My Mazda CX-5 is the first, and the only one, if I use the special 4.8 quarts, it reaches only to the half between the Add and Full. Most people here won’t use 4.8 quarts as specified in the manual either, but 5 quarts.

Strangely for my 2018 Toyota Yaris iA, a Mazda2 in disguise, its 1.5L specifies 4.4 quarts in the manual, and that’s all I need to make the oil level to the Full mark. Another recent oil change for my daughter’s 2022 Toyota Corolla Hatchback XSE with a 2.0L for the first time, the manual says 4.4 quarts, and that’s the amount I need to reach to the Full mark of the dipstick, no more no less.

Another unique “feature” from Mazda is, the torque specified in the manual is in a wide range, but every other shop manual I’ve seen gives a single torque value, not a range!
 
Most of the time, the top mark is considered "Max" meaning not to be filled any higher, and the bottom mark is to "add oil". Technically anywhere in between those two is okay, so I grew up making sure it was right in the middle. I drove Chevys and Pontiacs. The same is true of Mercedes from what I am reading.

Bottom line is the only time you need to add oil is when you are near or below the bottom mark—not to fill from the midpoint to full. I feel people got into the habit of doing that when they drove engines that burned oil and they wanted to compensate for it.

Back then, I was aware of the dangers of overfilling then but more recently I learned about lost efficiency from having a full oil pan. Yes, full...not even overfilled.

Also, Mazda warns of these direct-injected engines "making oil" (fuel dilution) increasing the level over time, so combined with wanting to get the best economy, it's best to stay away from the max line, in my opinion.
 
You have multiple pieces between the oil pan and the dipstick port on the valve cover. There is going to be a set of tolerances on each of those pieces, including the gaskets between several of them. That’s going to introduce an error that I’d bet stacks up to at least 1 mm of potential variation. Add to that the length variation of the dipstick itself, and you’re at probably 3 mm of error in the reading, just due to allowable dimensional errors in the components.

There’s a reason why they give you a good half inch or more in the allowable oil level in the pan. If you’ve never owned an engine that didn’t nail the full mark after adding the nominal oil fill volume, you need to play the lottery, because you’re insanely lucky.
 
Bottom line is the only time you need to add oil is when you are near or below the bottom mark—not to fill from the midpoint to full. I feel people got into the habit of doing that when they drove engines that burned oil and they wanted to compensate for it.

Back then, I was aware of the dangers of overfilling then but more recently I learned about lost efficiency from having a full oil pan. Yes, full...not even overfilled.
Yeah, if you have an engine that consumes a noticeable amount of oil keeping the sump up the the full mark might be a good idea. Definitely if you are driving 400-500 miles a day in the summer.

Otherwise your engine won't know the oil is only halfway between the marks, although the oil temperature might be a bit higher and warm up more quickly. At least that's what I think.
 
Most of the time, the top mark is considered "Max" meaning not to be filled any higher, and the bottom mark is to "add oil". Technically anywhere in between those two is okay, so I grew up making sure it was right in the middle. I drove Chevys and Pontiacs. The same is true of Mercedes from what I am reading.
Your statement makes me wonder why we have such different experience on oil change. I had a couple of Chevy’s back then, and I poured in the said oil amount, and the oil level would always be at the Top / Full mark of the dipstick. As I mentioned earlier, even today, I put in the said oil amount in the manual on newer vehicles, it reaches the Max / Full mark of the dipstick all the time. The only exception is my Mazda CX-5. It’s off by almost 0.5 quart! This isn’t just on my 2.5L NA, but also on the 2.0L and the 2.5T. The spec says 5.1 quarts for the 2.5T, but most find it needs at least 5.5 quarts to the Max / Full mark.

In addition, Mazda manual says the rear differential needs 0.48 quart (or 0.37 quart for 2nd Gen CX-5), but in reality it needs about 0.75 quart to fill to the brim of the fill hole! This’s the “approximate” fluid quantity listed in the manual to its max I’ve ever seen!


Bottom line is the only time you need to add oil is when you are near or below the bottom mark—not to fill from the midpoint to full. I feel people got into the habit of doing that when they drove engines that burned oil and they wanted to compensate for it.
It can be the personal preference not to fill the fluid to the maximum level. But I always consider the more important “safety margin”. In fact that’s why almost every car manufacture set a fluid capacity to the maximum amount. My personal experience where my 2018 Toyota Yaris iA overfilled as usual by the dealer from Toyota’s new vehicle free maintenance actually saved my engine. The slow leak from the drain plug after the oil change and the long road trip from San Jose to LA, where the engine lost more than 2 quarts along the way without any warning! Had the dealer didn’t overfill the oil, I firmly believe the low oil pressure warning light would be on and we’d get stranded on the road, with engine damage by oil starvation!

My 2016 CX-5 consume some oil since new, and I want the oil level in full after each oil change to have a better safety margin, and avoid oil top-off before the next oil change.


Back then, I was aware of the dangers of overfilling then but more recently I learned about lost efficiency from having a full oil pan. Yes, full...not even overfilled.
Of course oil overfill isn’t good. But we’re talking about getting the oil in full, not over the full mark.


Also, Mazda warns of these direct-injected engines "making oil" (fuel dilution) increasing the level over time, so combined with wanting to get the best economy, it's best to stay away from the max line, in my opinion.
Oil dilution by fuel could happen but very rare. Here in this forum I’ve only seen a couple of reports in many years. Of course the Mazda’s 2.2L diesel is a different story, especially in early years.
 
You have multiple pieces between the oil pan and the dipstick port on the valve cover. There is going to be a set of tolerances on each of those pieces, including the gaskets between several of them. That’s going to introduce an error that I’d bet stacks up to at least 1 mm of potential variation. Add to that the length variation of the dipstick itself, and you’re at probably 3 mm of error in the reading, just due to allowable dimensional errors in the components.
A simple solution to your scenario: wait the oil to drain back to the oil pan fully with enough time, preferably overnight, then you’ll get a consistent oil level reading on the dipstick.


There’s a reason why they give you a good half inch or more in the allowable oil level in the pan. If you’ve never owned an engine that didn’t nail the full mark after adding the nominal oil fill volume, you need to play the lottery, because you’re insanely lucky.
“If you’ve never owned an engine that didn’t nail the full mark after adding the nominal oil fill volume”. Really? Assuming your “nominal oil fill volume” is from the factory spec in the manual, then all CX-5 owners should go to buy lottery tickets now ⋯ 😗
 
Oil dilution by fuel could happen but very rare.
Every single Mazda Skyactiv owner on this forum has fuel in their oil. It is anywhere from 1-5% by volume.

Of course oil overfill isn’t good. But we’re talking about getting the oil in full, not over the full mark.
I am actually talking about just having oil to the full mark. This will vary from engine to engine, but there is a point where you lose efficiency. Power and economy both increase with less oil in the pan.
 
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