Best weight oil for 93 Civic VX engine/tranny for Ecomodding ???

[93civicvx]

The vehicle was acquired in Dec of 2010 and is in need of an engine & tranny oil change. ( engine oil was changed by corner car lot at time of purchase and was the cheapest grade they had... and tranny oil was changed ? ).
I understand I can use the same oil of both...
What is the best ( safest ) weight/viscosity oil to use for these two with ecomodding in mind ?
Not sure if brand really matters as long as it's fully synthetic...
Read on the forum about 0W10 & 20, but not quite sure and wanted to run it by you folks who have been doing this much longer than I with solid results.
Looking forward to the responses so I can get this done asap !
Thanks Guys !
Douglas

[ChazInMT]

I have researched the tranny oil thing a lot. The slight difference in MPG from one to the next will be erased if the tranny fails due to the wrong lubricant. I settled on using the Honda recommended Honda brand manual transmission oil. If you look at other forums, this just seems to be the safest choice. The owners manual says regular motor oil may be used temporarily if need be, but to put the Honda brand fluid in at the first opportunity.

I use Mobil1 5-20 cause I can get it at Wally World for 23.50 for a 5 qt jug.

BTW Fram oil filters are crap, I get Purolator golds at Kmart, NAPA filters are the same as Purolators for 2 bucks more. They are very good filters for the best price.

[zonker]

if the motor is solid and gets good oil pressure, 0w30 mobil 1 will do.

[brucepick]

I agree with Honda tranny fluid. We're assuming it's a standard tranny?

Find out the original spec engine oil for your Civic and start there. My '97 is spec'd for 5W-30 but yours is an earlier generation. If it burns or leaks using whatever it was spec'd for, try something a bit heavier.

Remember the upper number in the oil weight is the only one that counts once its warmed up.

[93civicvx]

Yup, it has the standard 5-speed tranny.
Doesn't burn or leak oil. Has about 175k on the clock...

HONDA Civic manual recommends : Engine - API "Energy conserving II" 5w-30
Tranny - 5 speed - API "SF or SG" and then use a bar chart based on temperature of climate - I live on the East coast of Central FL...

I am interested in the 0W-30 as I believe it will be less friction in the motor & thus maybe eek out a bit of mpg's in my favor - just don't want to do it at the expense of my motor/tranny failing !

I would typically just use the manufacturers recommended, but I see so many people on this site recommending lower viscosity oils that it has my attention ! :-)