I'm planning to replace all of my driveline fluids (transmission, engine, front/rear diffs/power steering, bearing grease, transfer case) with full synthetics when the time comes and was wondering if any of you have noticed improvements in fuel economy after replacing one or more dino fluids with synthetics? I'll be using 5w-30 Royal Purple in the engine and Red Line everywhere else. I'll also add some Red Line Water Wetter to the radiator after it's flushed and begin loading my tank regularly with Red Line SI-1 , which is a fuel additive they claim cleans injectors, chambers, etc. I might wind up making other mods/ improvements, but haven't decided what. Maybe a flex fan or K&N filter.
My goal is 25 mpg or better @ 55 mph - right now I'm at 18.5 on the hwy at 65 mph running 10w30 Mobil 1 and conventional everything else. Think it can be done?
Hopefully, some minor HP gains can be realized from all of this as well. God knows Monty folks have little options when it comes to bolt on power. <img src="/forums/images/graemlins/frown.gif" alt="" />

Hey, I haven't really kept an eye on my exact fuel economy, but I also have a 97 with 32's on and use mobil 1 10W30 in the engine as well. I have factory Mitsu fluids in all the other systems from my 100k service. I would have to say that mobil 1 in the engine is a wise choice from 200k miles of experience on our old '91 Montero, but I don't know about any benefits from putting synthetics in other systems of the vehicle. If I determine my gas mileage, I will let you know, but I thought it was better than 18.5 on the highway. Good Luck.

Scottie

you should definitely see improvements in both economy and power. 25mpg might be a little optimistic though (unless you *drop* the suspension and put some skinny, high-pressure tires on).

nearly two years ago i put 75w-90 amsoil in both diffs and the transfer case, 5w-30 amsoil in the motor, and amsoil ATF in the tranny. mileage improved slightly...from 16-18mpg to 18-20, about 4-5%. myself, i wouldn't mess with fuel additives.

i don't have personal data on power improvements, and i know there is some skepticism that oil can add power, but i did see an article in 'Roundel' (the BMWCCA magazine) a while back that documented this, at least on a little 4 cylinder.

they dynoed a 318ti with petroleum lubricants, then drained it and refilled with equivalent weight mobil 1 synthetics, and dynoed it again. this is a ~140hp 1.8l motor, with a manual tranny and LSD. my recollection is that they made an extra ~7hp.

in the monty, it would seem to me that with bigger parts and more gearboxes, the frictional losses would be higher. so hopefully the gains from synthetics would be higher as well.

finally, stay away from the K&N. it flows better, and will improve milage slightly, but it doesn't filter worth a damn.

fwiw,

Synthetics in driveline components are good, but I wouldn't put anything routinely in my fuel tank. About every 15,000 miles I'll add a can of BG-44k. Breaks down any valve deposits and cleans up induction.

Ed

Dadrab, I heard about the BK stuff but I can't find it in my local parts stores (Kragen, Autozone, PepBoys). Where do you get yours? TIA for any help.

Erick,

It's only sold through shops and not through pep boys, etc.

You can also find it at Stevens Creek Mitsubishi.

BG's website is www.bgprod.com where you can find the local service centers they sell to.

Ray

My local Pep Boys sells BG-44K. You need to move to a less disadvantaged area. <img src="/forums/images/graemlins/lol.gif" alt="" />

Seriously, ask at the counter... they might be able to order it.

Frank

My bad... I guess Pep boys does have a service area... <img src="/forums/images/graemlins/lol.gif" alt="" />
<img src="/forums/images/graemlins/kewl.gif" alt="" />

Although when I went to my local pep boys they didn't carry it. Then again, that was a few years ago when the merit's of BG-44k were first brought to light on this forum.

What Offroader said. Any high end japanese automotive parts department will have it.

Ed

You aren't gonna get 25mpg.

But you might see it go up a little.