My owners manual seems pretty adamant about using a motor oil designated as "Energy Conserving". And this makes sense. But I have yet to come across a "For High Mileage Engines" oil rated as being energy conserving. I have two questions:

First, Are so-called "high-mileage" formulas so much different and will it make a difference in my car? (which has 235,000 miles. High indeed)

And Second, if forced to choose between a high mileage formula and a motor oil rated as being energy conserving, which should I opt for? So far I've gone by the book and use an Energy Conserving oil. I don't typically trust marketeers over engineers.

 

Energy conserving motor oils tend to be lighter weight than other motor oils. High-mileage motor oils tend to be heavier weight than other motor oils.

I would say that if you have successfully been uisng energy conserving motor oils and do not experience too much oil consumption, I would stick with them. I would say that if you burn much more than a quart of motor oil between oil changes, you might want to consider using a high mileage motor oil to reduce the oil consumption. You loss in gasoline mileage will probably be difficult to measure.

 

If it ain't broke don't fix it. Specifically, what motor oil have you been using?

 

Valvoline 10w30. Currently i experience little to no oil consumption between 3000 miles changes. Any loss is negligible anyway.

But with 236000 miles i would deffinately consider myself high-mileage and was just wondering what made "high-mileage" oils "better" for engines such as mine. Maybe they just mean american engines with over 75,000... that tend to be where they start going. I wouldn't be surprised if i could get atleast half a million out of mine, if the rest of the car cooperates

 

I would stick to what you are doing. If you are not burning any oil between changes, you certainly don't need high-mileage motor oil.

Given the mileage on your engine, I would resist the temptation to go to synthetic motor oil.

 

Right now it's all about "not upsetting the balance"