honda, why 10w30

[nicholas]

hey everyone,

i wanted to know why honda says to use either their MTF, or 10w30 motoro oil in the transmission case, when most other std transmissions use 75w-90 gear oil.......

so far i have been using 5w30 oil for the winter, and 10w40 conventional for the summer, and after two years it still shifts like butter,

it is a 2000 Si Civic

just wondering if there are any honda guru's out there.....
have a good long weekend
nik

 

[carrera79]

My SAAB calls for 10w30 as well. I think that the motor oil may be capable of handling more heat stress than equivalent gear oils. It also seems that all of the people in SAAB world taht talk about premature failures of SAAB transmissions are the ones who switched to gear oil.

 

[Whimsey]

I'm not a Honda guru but my brother-in-law is

. Most likely for ease of shifting when cold. Many American vehicles with manual transmissions use ATF instead of gear oil for that reason. If the transmission was built to use motor oil or ATF you might cause unforseen problems by using the thicker gear oil, other than just tougher shifting.

Whimsey

 

[HOndaGuy]

Just use redline mtl in your transmission(meets all your specs and doesn't cost that much more than the regular honda mtf). I have an 02 civic ex 5 spd that I plan on putting it in next week.

 

[Bror Jace]

"... why Honda says to use either their MTF, or 10W30 motor oil in the transmission case, when most other std transmissions use 75W90 gear oil ..."

No. Most transmissions no longer spec gear oils. In the last few years, most have moved to a lighter synchromesh fluid.

Very few makes (VeeDubbs?) use traditional gear oils in their transmissions anymore.

"I have been using 5W30 (syn blend) oil for the winter, and 10w40 conventional for the summer. After two years it still shifts like butter."

Change it often. Those lubes are not terribly shear stable nor do they have the robust additive packages ideal to protecting clashing gears.

I used MTL in my Hondas and a mix of MTL/MT-90 in my Nissan which requires 75W85 GL-4 (Synchromesh gear oil).

--- Bror Jace

 

[Idrinkmotoroil]

I've wrenched on Hondas for many years. Firstly Honda MTF is an excellent product it works very well in their transmissions for a number of reasons. Regular motor oil does not have the proper additives for transmission operations. I'm very surprised your car is working so well with motor oil up til now. I've owned many Hondas including a 99 SiR and I always swore by Honda MTF. I just liked to change it at least once or twice per year, I found it kinda wore out after a while. If you read the manual I think you will find that it says you can use motor oil if you dont have Honda MTF available but it recommends you swap in Honda MTF at the first available opportunity. They dont want you to run motor oil on a regular long term basis.

The Redline MTL would be a second choice but I dont think it would shift any better than the Honda MTF. I've always believed Honda MTF to be a good synthetic based fluid, if not at least semi synthetic.

As mentioned above manufacturers do not want to hear complaints about hard shifting in cold weather situations. Most people nowadays expect transmissions to be 100% perfect in all conditions and would not accept a bit of roughness in cold temp operations. So the move to thinner fluids is becoming common place. Manufacturers are moving away from thicker gear oils for less customer complaints in cold weather transmission operations. Honda MTF is likely somewhere around a 5w30 weight viscosity, its not overly thin (like ATF) but the synthetic base helps it work well in cold temps. I'd strongly recommend using it in your transmission and swap it out on a regular basis , cheap maintenance.

[ May 29, 2004, 01:16 AM: Message edited by: Idrinkmotoroil ]