Short trip VS Viscosity

[Graham Piccinini]

Lots of threads on this topic and lots of conflicting information. Which of these two theories is correct? Both have been posted and/or confirmed by knowledgeable members in one way or another. But contradiction creates doubts, and I would greatly appreciate if anyone could shed some light on this. Preferably through facts and not guesses/speculation... Thank you in advance.

Theory 1: In short tripped vehicles, with low rpm cruising and/or rare use, it is best to use the oil of lowest viscosity available. It will flow faster and be the quickest to get up to temp, but it's final operating temps will be lower. Many argue that lower film thickness is a problem, but easier flow and pump-ability balance that off.

Theory 2: In short tripped vehicles, with low rpm cruising and/or rare use, it is best to use oil of a higher viscosity as it will heat up faster through frictional drag, and final operating temps will be higher, aiding in moisture burn-off. Here many argue that it provides higher fluid film thickness, at the cost of cold start-up protection, but gives better overall protection, and aids with fuel dilution that short tripped vehicles are known for. (talk about run-on sentences)

So which one is it? Or maybe both? Is mid-grade (like 5w30) the ideal place to be for any internal combustion engine? Discuss...

 

[Hogwash]

I'm far from an expert. But my wife's '19 Corolla is short tripped quite often. It's spec'd for 0/20. I found that M1 EP 5/20 is a heavy 20 with a 9 at 100° C. That's heavier than any other 20 that I could find. So that's what I use.

I feel better about using a 20w...especially under warranty. But I also like the idea of one a little more robust.....even if it's just in my head

 

[demarpaint]

I know where you're coming from with this topic, and I have a feeling you're going to see a repetition of the past "thick vs. thin" discussions/wars. I followed threads like this closely for many years on Bitog. I won't beat the dead horse with my reasoning, but I have come to the conclusion that 0W 30 or 5W30 in my applications and usage patterns gives me the best of both worlds. I consulted people I felt who were experts, on Bitog or in the automotive world to help me arrive at my decision.

 

[wpod]

I usually ask and will ask what are we expecting form the oil choice. Less wear better mpgs etc.

 

[KCJeep]

Thicker oils (#2) do warm up a bit faster than thinner ones in my experience. Does it make any difference in your use pattern? You be the judge.

 

[ofelas]

On gasoline vehicles spec'd for 20/30 grade -

I like a 3.5+ HTHS oil for short winter trips, to protect a bit better against fuel dilution.

Then, I like a 3.5+ HTHS oil for spirited summer trips/higher rpms.

Wait, looks like I use a 3.5+ HTHS 5w30/10w30 oil year round

 

[OM605]

Wait, looks like I use a 3.5+ HTHS 5w30/10w30 oil year round

3.5+ HTHS 10W30? Is it a HDEO?

 

[Graham Piccinini]

I usually ask and will ask what are we expecting form the oil choice. Less wear better mpgs etc.

Well, we can't gain something without losing something elsewhere. Always a compromise. But which compromise is the most favorable for a short tripped vehicle?
Vehicle in question is a 2009 Tacoma from my signature. It took my dad 10 years of daily driving to rack up 47k miles, and at least 10k of those miles are done by me with occasional errands with highway driving. Rest of the time it does 5-7 miles per day total, Mon-Fri.

 

[ofelas]

No, it's a gasoline oil - https://amsoilcontent.com/ams/lit/databulletins/g2883.pdf

3.5+ HTHS 10W30? Is it a HDEO?

 

[JMJNet]

What do you mean by thicker? xw-20 vs xw-30?

IMO, I don't think it matters because even between those 2 thickness are within the spec so it should make too much difference.

 

[kschachn]

Theory 2: In short tripped vehicles, with low rpm cruising and/or rare use, it is best to use oil of a higher viscosity as it will heat up faster through frictional drag, and final operating temps will be higher, aiding in moisture burn-off. Here many argue that it provides higher fluid film thickness, at the cost of cold start-up protection, but gives better overall protection, and aids with fuel dilution that short tripped vehicles are known for. (talk about run-on sentences)

"Cold start-up protection" is provided by a higher film thickness, just as it is during all other modes of operation.

 

[ka9mnx]

I would use what the folks that designed the engine say to use. They have taken every conceivable driving situations into consideration with their recommendation.

 

[ofelas]

Cream & sugar with that CAFE, anyone?

I would use what the folks that designed the engine say to use. They have taken every conceivable driving situations into consideration with their recommendation.

 

[Graham Piccinini]

I would use what the folks that designed the engine say to use. They have taken every conceivable driving situations into consideration with their recommendation.

But they also have to take into consideration that EPA is only happy when CAFE regulations are met, meaning give up viscosity and some protection for the sake of MPG and emissions. And if EPA isn't happy, then huge government fines come into play. It's cheaper to just spec a "lighter" grade and give up long term reliability for the 3rd, 4th, 5th owner of the car, than it is to spec the absolute best oil grade on the market. Geographics and product availability come into play too. A Camry engine in states will spec a 0w20 in the owners manual, but a Camry with exact same engine from the same assembly line and possibly same "batch" will list oil grades from 0w20 up to 20w50 as acceptable oil grades for that engine. Why? CAFE regulations and lawyers. Anyways, back on topic, so which side of the spectrum do you think is best for a short tripper?

 

[Graham Piccinini]

"Cold start-up protection" is provided by a higher film thickness, just as it is during all other modes of operation.

100% agreed. I worded it wrong in my original post. I guess what I meant to say was "cold start-up flow", which is often synonymized with "cold start-up protection". That alone is an argument in it's own though...

 

[Graham Piccinini]

What do you mean by thicker? xw-20 vs xw-30?

IMO, I don't think it matters because even between those 2 thickness are within the spec so it should make too much difference.

I mean how would an engine be in terms of performance, MPG, oil consumption after 200k of short tripping on 0w20 vs 15w40.
Obviously the 0w20 will give better MPG, but at what cost? Possibly a premature timing chain/component issue? On the other hand 15w40 would give thicker fluid film, but at what cost? Could it cause premature cylinder wear due to cold weather start-ups? Would a 5w30 be perfectly enough to cover the middle ground between the two spectrums?

 

[tundraotto]

3.5+ HTHS 10W30? Is it a HDEO?

Mobil 1 10W-30 HM has an HTHS of 3.5

M1 10W-30 (non-GF5) High Mileage now SN Plus

For those concerned about LSPI but want a proper 30 weight oil (10W-30 HM is a non-GF5 oil, HTHS 3.5), Mobil 1 10W-30 High Mileage is now SN Plus. I just had some delivered from Walmart for the Fall rebate and was surprised to see SN Plus on the bottle, even though M1’s webpage only lists SN...

bobistheoilguy.com

 

[ofelas]

Don't happen to have a pic of the current bottle/jug, by any chance?
I wouldn't mind trying it out (or 5w30 ESP) in a roller tappet engine.

Edit - can't seem to find it up here in Canada, just one 10w30 offering from Mobil locally - anyone know what the HTHS/NOACK values are for this - https://www.canadiantire.ca/en/pdp/mobil-1-10w30-synthetic-engine-oil-4-73-l-0289451p.html#srp

 

[kschachn]

100% agreed. I worded it wrong in my original post. I guess what I meant to say was "cold start-up flow", which is often synonymized with "cold start-up protection". That alone is an argument in it's own though...

Well the same principle applies to “flow” as well since unless the oil has jelled in the sump and cannot be pumped then flow isn’t an issue. The bottom line is that most wear does not occur during start but rather during warmup and that’s not connected to insufficient MOFT nor flow.

There really isn’t ever a problem with “startup wear” with any oil.

 

[ofelas]

Fuel dilution/idle enrichment, I assume?

most wear does not occur during start but rather during warmup and that’s not connected to insufficient MOFT nor flow.