Maintenance intervals v. Highway miLes

[SpecE30]

I drive 750 miles/week, 95% highway miles. Can I extend my maintenance intervals for gearbox oil, diff oil, coolant, etc, based on the notion that my actual engine hours are way fewer than what 50/50 city/highway use would be? For example, I reach 30,000 miles at least a year quicker than the average driver. NO NEED TO WEIGH IN ON Oil change INTERVALS.

 

[Gabe]

What are you driving??

 

[Turk]

Extend your gear/diff/coolant an equivalent rate as your engine due to the fact that they run at an equivalent rate.


Oh, wait, nevermind.

Anyway,

 

[daman]

Yes,heck most people don't even change it at all.

 

[Sam_Julier]

How long do you plan to own the vehicle?

 

[Doug Hillary]

Hi,
Spec#30 - Welcome to BITOG. You don't tell us the vehicle and its configuration?

In my heavy truck fleet - Eaton/Rockwell - I changed the lubricants to a conforming synthetic when new (no more than 5kkms) and then via used oil analysis changed the lubricants around 1m kms

Im my cars it is a changeout with conforming synthetics within about 3kkms - then check only until sale!

 

[JHZR2]

Originally Posted By: Sam_Julier
How long do you plan to own the vehicle?


This is a consideration unfortunately... But Id just change it at least once to get the junk out and then Id say yes. The caveat of UOA is a sound one, otherwise you are guessing...

 

[gfh77665]

I am in the same situation. 98% highway driving. These are EASY miles for the trans. Temps stay cool and pressures mostly constant. Instead of the 15K to 30K interval, I change at 50K, alternating between pan drop + filter and the non pressurized coolant exchange. I have never, ever had a trans problem.

 

[mechtech2]

Coolant should be the same.
Trans, diff, and gearbox oil should actually wear more with higher speeds and loads.

 

[gfh77665]

So you are saying that stop & go city driving, with the trans constantly shifting is easier on it than cruising at a constant highway speed, where radiator cooling is most efficient?

 

[SpecE30]

Here's more info, then I am curious about the reply.

Car is a 2008 BMW 128i, 6MT. Bought it with 35,000 miles. I immediately changed diff and gearbox (supposedly lifetime fills) with Red Line synthetics. Coolant changed with OEM coolant. Using a 30,000 mile change interval for the diff/gearbox, two years for coolant. Car now at 68,000 miles. Have changed diff/gear fluid again.

But do I need a 30,000 mile change interval? I can understand that mileage on the drivetrain is regardless of sitting in traffic, so maybe using mileage is best. But then, if one drives 10,000 miles a year,that would mean these fluid stay in the car 3 years, versus 10 months for me. Does that matter.


As for engine use, I generally cruise at either 65 or 75 mph. Equals 2400 or 2800 rpm.

 

[mechtech2]

Originally Posted By: gfh77665
So you are saying that stop & go city driving, with the trans constantly shifting is easier on it than cruising at a constant highway speed, where radiator cooling is most efficient?


I said the cooling should be the same.
And, I said trans, diff and gearbox OIL , not the gear systems.
The lube should wear faster from shear and more heat.