Oil Capacity

[opus1]

Been pondering this one for a while.

The Cobalt has a 2.0L engine, 5qt oil capacity. And I understand that the Supercharged engine had a 6 or 6.5 qt capacity.

The Ranger has a 2.3L engine, 5qt oil capacity.
The Malibu has a 3.1L engine, 4.5 qt oil capacity.
The Dakota has a 3.9L engine, 4qt capacity.

What determines an engine's oil capacity? More importantly, why would the largest engine have the smallest capacity?

 

[bepperb]

Really just a stamped metal oil pan.

My HL has a 4.5 quart sump. Around 2005 they inreased this via a larger oil pan to a little over 5quarts. Just a different pan.

The same size engine in the Accord is 5.5 quarts. Probably because Honda uses a longer drain interval.

 

[Quattro Pete]

I'm guessing it's a combination of conflicting factors such as amount of available space under the hood, time to reach operating temp, cost of maintenance, etc.

But it is an interesting question and I'm curious to hear an answer too.

 

[MoparDak05]

Originally Posted By: opus1
The Dakota has a 3.9L engine, 4qt capacity.

Yeah, it is rather odd considering my '05 3.7L Dakota requires 5 quarts.

 

[opus1]

Originally Posted By: MoparDak05
Originally Posted By: opus1
The Dakota has a 3.9L engine, 4qt capacity.
Yeah, it is rather odd considering my '05 3.7L Dakota requires 5 quarts.

And it is accurate. I thought there was a misprint, but the owner's manual agrees with the service book, and if I put in 4.5 quarts, the dipstick definitely shows it's over-full.

 

[rcy]

Speaking of capacities, why would the engineers even make 1/2 quart sumps. Why not just round up to an even number so instead of 4.5 make it 5. That way one could just dump in 5 quarts (or 6 or 7 or whatever) and not have an extra 1/2 quart laying around.

 

[bdcardinal]

most likely due to packaging issues.

 

[ls1mike]

The GMC takes 8 quarts...Ugh. 3000 mile oil changes because all it does is tow.
The Trans Am is 5.5 with filter about half of the guys who own them just put 6 qts in. That is what I have been doing for about 12 years in my LS1 cars.
I have always wondered how accurate dipsticks really are.

 

[wapacz]

Going with packaging also. If there is a max height an engine can be and the bigger engine they want to stuff in is too tall. They have to remove that extra height some where.

 

[Quattro Pete]

Originally Posted By: rcy
Why not just round up to an even number so instead of 4.5 make it 5.

But what if the same engine is sold in Europe? They use 1 liter bottles there, and 5 quarts = 4.73 liter. That's not particularly even...

Quote:

That way one could just dump in 5 quarts (or 6 or 7 or whatever) and not have an extra 1/2 quart laying around.

Keep the leftover for top ups.

 

[rcy]

OK...make it in litres then...and...you Americans can switch to metric!!!!

Luckily, I don't need to top up my vehicle, but I see your point..

 

[Benzadmiral]

The 4.2 liter engine in the Mercedes 420SEL needed 8 quarts. The 2.3 4-cylinder in my C230 took 6. The Germans really believe in having lots of oil!

 

[rcy]

My Outback H6 (3.0 litre) took almost 6 quarts. The Lexus RX350 (3.5 v6) takes almost 6 quarts as well. I think 'the more, the merrier'.

 

[Kruse]

Originally Posted By: opus1

What determines an engine's oil capacity? More importantly, why would the largest engine have the smallest capacity?


There are a lot of inline 6 cylinder engines that take extra oil.(some Ford 300 engines take 7+quarts)
Remember that in a lot of V8 engines, the crankshaft really isn't any longer than an inline 4 cylinder, so you don't need as much oil to fill up the crankshaft.
A lot of times oil capacity is determined by other factors other than cubic inches.
Still, I have a Dodge 3.9 and I feel that it should hold more than 4.5 quarts, but it's been a decent engine.

 

[artificialist]

One thing I consider weird is that some Nissan Sentras built between 1995 and 2004 required 3 quarts of oil. I replaced an oil pan on one, and I could plainly see that Nissan could have easily made the pan larger.

 

[The Critic]

The VQ35DE in the Altima has a 4 7/8 qt oil capacity. What a pain!

 

[El_Schaf]

Originally Posted By: The Critic
The VQ35DE in the Altima has a 4 7/8 qt oil capacity. What a pain!


LOL, sounds like 5 to me

 

[Jonny Z]

Originally Posted By: Benzadmiral
The 4.2 liter engine in the Mercedes 420SEL needed 8 quarts. The 2.3 4-cylinder in my C230 took 6. The Germans really believe in having lots of oil!


For their long drain spec.

 

[bigmike]

Originally Posted By: El_Schaf
Originally Posted By: The Critic
The VQ35DE in the Altima has a 4 7/8 qt oil capacity. What a pain!


LOL, sounds like 5 to me


Sounds about right.

1+1 = 3 for large values of 1.

 

[willix]

Older N*, 7.5 qts. capacity won't put the level to "full", 8 qts. to full on the stick.