Honda's like thick or Thin oil?

I am going to be doing a 6 day, 7500 km run accross Canada next week. I have
a 99 Accord 4 Cyl with 100k kms on the clock. Right now I use Mobil 5w30
with slight consumption (ie. 1 Liter/7500 kms). I understand that Mobil is a
"thin" 30 weight and have been considering making the switch to German
Castrol 0w30 which is a "thick" 30. Has anybody used this oil before or even
a 40 weight in their 2.3's? Will I experience any real drop in MPG and will
I cause any harm to my engine by using a slightly thicker oil in my car? I
am trying to strike a balance between Valvetrain protection and MPG. Any
input is greatly appreciated.

 

You're valve train won't be under much stress on a long cruise like that. Go
light.

 

10W30. You won't need much start-up lubrication on a long cruise, so
you don't need 0 or 5 on the front end even in Canada, eh? 10W30 will
get you all the way through the trip without the additives starting to
break down, something that 5W30's cannot do. Or can you get 10W30
there?

 

I don't think that was the point. Not all XW-30 oils are of the
same thickness.

There are variations in the typical thickness of XW-30 oils depending
on formula. The allowable variation in viscosity at at 100°C is from
9.3 to 12.5 cSt. Mobil 1 5W-30 has a typical value of 10.0, while
"German Castrol" 0W-30 has a typical value around 12. This "German
Castrol" is a green-colored, gummi-bear scented 0W-30 oil that is
labelled as meeting several German automakers' (Mercedes-Benz, VW/Audi,
BMW, Porsche) specs as well as ACEA A3 (extended-drain). It is made
in Germany and doesn't carry an "Energy Conserving" rating, and is
relabelled as Castrol Syntec. A US made version of Castrol Syntec
0W-30 doesn't meet those standards, does carry the EC rating, and
is reputed to be about 10.5 cSt at 100°C.

I believe that at cold startup at summer temps, this Castrol 0W-30
might even be thicker than Mobil 1 5W-30. Also - I've heard from
some sources that Mobil 1 no longer needs VI improver for its
"SuperSyn" 5W-30, and that it holds its viscosity for a very long
time.

<http://www.castrol.com/liveassets/bp_internet/castrol/castrol_usa/STAGING/local_assets/downloads/p,q/pds_syntec_usa.pdf>
<http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil1_5W-30.asp>

I'd stick with the Mobil 1 5W-30. It's good stuff and easy to
find if you need to top off.

 

screw the MPG. any difference is negligable. stick with mobil1 5w30, IMO.

 

My 02 Civic Si/Sir loves the 5w30 Mobil 1. Since you have GC exposure you
must have seen some M1 UOA's from BITOG. I caught the bug and sent off for
an oil analysis. But for the most part, Honda I4's are pretty easy on oil
and I don't think the thickness of GC will do anything for you. If anything
run the new Mobil 1 EP, I have it in my crankcase now but the following UOA
is from standard Mobil 1, which I have used consistently since about 18k,
Castrol GTX before then for proper dino break in. My Mobil 1 OCI is between
7500 and 9000 miles. As you can see, wear is extremely low. This car is
not babied, but driven with best practices in mind like proper operating
temperature and the occasional long highway cruise.

http://home.comcast.net/~marcoat/oilanalysis.JPG

 

ExxonMobil has reformulated Mobil 1 5W-30. The product data now says
that the "typical properties" for regular Mobil 1 5W-30 include 11.3
cSt (was 10.0) viscosity at 100°C. I've got one jug of SL-labelled
Mobil 1 5W-30, and two SM. Of course I can't know if they might have
made the switch before relabelling for API SM. Oil companies change
the formulations of their products all the time without any relabelling.
It wouldn't surprise me if Mobil started selling the API SM version
before they could officially relabel as such.