Oil consumption rise after changing oil type.

[uart]

I recently decided to try a new oil in my wife's 2005 Prius (at 310,000 km). Previously I've (mostly) been using Castrol Edge 5W30 A3/B4, but recently I changed to Penrite Enviro+ GF5 5W30.

I've not been unhappy with the performance of the new oil, the engine is still running sweet and cold starts sound smooth and all, but I've noticed a fair bit of a jump in oil consumption since the latest change.

I guess that the Penrite oil is probably one that not too many here would know a lot about, being a local Australian blender. However I don't think it's a bad oil, it's SN, GF5 and certified Dexos1.

Mild to moderate oil consumption is very common in higher mileage gen2 Prius, so my previous oil consumption of about 300mL per 3000km (2000 miles) was no great concern to me, but since changing to the new oil it seems to have suddenly risen by somewhere around 50% to 75% more.

Just wondering if viscosity differences alone could account for the difference in oil consumption, or if there is something else going on.

The Castrol has a KV of 72/12 cSt (@40/100C), CCV 6500 cP @-30C, and HTHS of 3.6 cP.
The Penrite has a KV of 63/11 cSt (@40/100C), CCV 4850 cP @-30C, and (I think) HTHS of 2.9 cP.

Penrite Data Here
Edge Data Here

 

[Shannow]

HTHS (and the other viscometric factors around it) are IMO probably the major causative.

Volatility in the lighter GFs cold help in consumption too.

 

[uart]

Yeah, there's a fairly big viscosity difference there despite them both being 5w30's.

I'm not sure about volatility differences as neither of them seem to publish noack figures. But yeah, the lighter Enviro oil could have higher volatility.

The Enviro+ stuff definitely has better cold cranking properties, and if I lived in an Alpine region it might even make a worthwhile difference, but up here in Newcastle where temps are over +10C 99% of the time I don't think there is any meaningful benefit.

I've used all my Edge 5w30 stash now and the Enviro just seemed like a good price for a "full synthetic" (about $42 pre 5L bottle on supercheap auto's 20% off days).

Next change I might just go with Magnatec 10W30 as that can always be had at a fairly decent price here. And the old prius definitely doesn't need anything too special.

 

[Shannow]

Originally Posted By: uart
Next change I might just go with Magnatec 10W30 as that can always be had at a fairly decent price here. And the old prius definitely doesn't need anything too special.

That's exactly what I was going to suggest...but didn't

 

[uart]

Originally Posted By: Shannow

That's exactly what I was going to suggest...but didn't


You know what they say, great minds think alike.

 

[Brons2]

That's an A3 rated oil versus what looks like a US/API spec oil, not surprised it's consuming more oil.

Try an A3 rated Penrite, see how that goes. I bet it slows consumption.

I'm not convinced Magnatec will help if the specs are more like the Penrite, even though it's 10w30. I'd stick to an A3 rated oil or similar if that was working for you. Or just go Xw40.

 

[uart]

Originally Posted By: Brons2
That's an A3 rated oil versus what looks like a US/API spec oil, not surprised it's consuming more oil.


Yes it's an A3/B4 rated oil up against the more fuel economy conscious Dexo1 rating. And there's a fair bit of viscosity difference despite them both being 5w30's.

The Magnatec 10W30 is also ACEA A3/B4 rated, so hopefully it will behave more like the Edge. Being a 10W oil of course it has poorer cold cranking properties than either of the previous two, though I don't think that will bother me too much in this climate.

The key Magnatec viscosity specs are:

KV = 84/12.4 cSt (@ 40/100C). CCV = 6640 cP (@ -25C) and HTHS >= 3.5 cP (as per A3/B4 specs).

Magnatec data: here.

 

[CELICA_XX]

I had the same problem with an almost identical engine (1NZ-FE)

When I finally decided to switch to Valvoline MaxLife Full Synthetic, my oil consumption dropped SIGNIFICANTLY.

 

[uart]

Originally Posted By: CELICA_XX
I had the same problem with an almost identical engine (1NZ-FE)

When I finally decided to switch to Valvoline MaxLife Full Synthetic, my oil consumption dropped SIGNIFICANTLY.


It's funny, I was also thinking about trying the Maxlife when I noticed the recent oil consumption rate on the Enviro+ oil.

Unfortunately it's very hard to find around here. The best I could manage to find was some overpriced semisynth (red bottle) in 20W50 at about $50 per 5L bottle. No other grades available

so I passed on that!

 

[bigj_16]

Originally Posted By: uart
Originally Posted By: CELICA_XX
I had the same problem with an almost identical engine (1NZ-FE)

When I finally decided to switch to Valvoline MaxLife Full Synthetic, my oil consumption dropped SIGNIFICANTLY.


It's funny, I was also thinking about trying the Maxlife when I noticed the recent oil consumption rate on the Enviro+ oil.

Unfortunately it's very hard to find around here. The best I could manage to find was some overpriced semisynth (red bottle) in 20W50 at about $50 per 5L bottle.

Anyway I passed on that!

Yeah, but that is $50 AUD. That doesn't count.

 

[LeakySeals]

I get that changing oil brands on some vehicles I've owned. Especially switching over to M1. After 2-3 OCI's consumption goes back to or close to what it was before. Only reason I can come up with is the time it takes for the diff brand oil to replace the coating/glaze the former oil has on moving parts like the cyl walls and valve seals. And for others there is an issue with consumption, and the oils that don't creep and flow as well cause less burn off. Or.. Whats the flashpoint of each? Maybe some is really "burning"

 

[Kuato]

We have seen this in numerous posts...some cars will drink certain oils. Switching back should cure the issue.