# "High mileage" motor oil for older cars **URL:** \ **Category:** Factual Questions\ **Created:** [June 23, 2010, 10:37pm UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282 "2010-06-23T22:37:07Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [June 23, 2010, 10:37pm UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/1 "2010-06-23T22:37:07Z")
Worth the extra cost? Thanks! ---
**Author:** ![thirdname](https://avatars.discourse-cdn.com/v4/letter/t/d07c76/32.png) [@thirdname](https://boards.straightdope.com/u/thirdname)\ **Post date:** [June 24, 2010, 1:11am UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/2 "2010-06-24T01:11:59Z")
I’m sure an expert will chime in, but I believe from listening to car shows that the only benefit is that they resist being burned away in heavily worn engines. If you have an older car that is worn down and is burning oil, they will reduce the rate of that. If your car isn’t burning oil, there is no benefit. ---
**Author:** ![JoeH2O](https://avatars.discourse-cdn.com/v4/letter/j/9de053/32.png) [@JoeH2O](https://boards.straightdope.com/u/JoeH2O)\ **Post date:** [June 24, 2010, 5:03pm UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/3 "2010-06-24T17:03:41Z")
The “vintage” motor oils also exclude the detergents that are often found in modern oil that tend to degrade the years and years of deposits that have built up over the years in old engines that potentially causes more harm than good. If it reaches that age and is still running fine, you want to do as little to disturb it as possible. ---
**Author:** ![zwede](https://avatars.discourse-cdn.com/v4/letter/z/ac91a4/32.png) [@zwede](https://boards.straightdope.com/u/zwede)\ **Post date:** [June 24, 2010, 5:41pm UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/4 "2010-06-24T17:41:38Z")
High mileage oil typically has two things: 1. It is heavier viscosity (thicker) to reduce oil burning. 2. It has a seal conditioner that makes seals and gaskets swell to reduce/stop external oil leaks. If you are currently running a regular oil and it is not burning or leaking, stick to regular. If you are having problems with the engine using oil and/or leaking, you could try the high mileage. ---
**Author:** ![SanDiegoTim](https://avatars.discourse-cdn.com/v4/letter/s/85e7bf/32.png) [@SanDiegoTim](https://boards.straightdope.com/u/SanDiegoTim)\ **Post date:** [June 24, 2010, 8:10pm UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/5 "2010-06-24T20:10:31Z")
If the climate in which you live is moderate/warm, just use a heavier weight oil. And if you’re burning it, don’t buy anything expensive. ---
**Author:** ![DogRatCat](https://avatars.discourse-cdn.com/v4/letter/d/8e8cbc/32.png) [@DogRatCat](https://boards.straightdope.com/u/DogRatCat)\ **Post date:** [June 24, 2010, 8:21pm UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/6 "2010-06-24T20:21:27Z")
Jiffy Lube charges (and I assume profits) more for High Mileage oil. Ka-Ching!!! ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [June 24, 2010, 10:40pm UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/7 "2010-06-24T22:40:29Z")
> [@JoeH2O](#): > > The “vintage” motor oils also exclude the detergents that are often found in modern oil that tend to degrade the years and years of deposits that have built up over the years in old engines that potentially causes more harm than good. If it reaches that age and is still running fine, you want to do as little to disturb it as possible. You are confusing vintage motor oils with high mileage motor oils. Older engines with flat tappets used an oil high in zinc and phosphorous. A compound called ZDDP is what carried the zinc and phosphorous. Modern oils have much less zinc and phosphorous and can cause actual damage if used in a flat tappet engine. This has lead to some oil makers producing “classic” motor oils for these older engines. Not the same as a high mileage oil that has additives to help rejuvinate bad seals. ---
**Author:** ![SanDiegoTim](https://avatars.discourse-cdn.com/v4/letter/s/85e7bf/32.png) [@SanDiegoTim](https://boards.straightdope.com/u/SanDiegoTim)\ **Post date:** [June 24, 2010, 11:31pm UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/8 "2010-06-24T23:31:26Z")
Another solution to the ZDDP-less products is motor oil designed for diesel engines. As Rick notes, it’s not a big issue with newer cars, but with older ones it can be. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [June 24, 2010, 11:37pm UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/9 "2010-06-24T23:37:23Z")
Whats considered an “old” engine? I have an inline 6 cyl 252?, circa 1982. I rebuilt it awhile back and I seem to recall flat tappets. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [June 24, 2010, 11:43pm UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/10 "2010-06-24T23:43:55Z")
> [@SanDiegoTim](#): > > Another solution to the ZDDP-less products is motor oil designed for diesel engines. As Rick notes, it’s not a big issue with newer cars, but with older ones it can be. I thought diesel engines used fuel as lubricant. ---
**Author:** ![Baracus](https://avatars.discourse-cdn.com/v4/letter/b/2bfe46/32.png) [@Baracus](https://boards.straightdope.com/u/Baracus)\ **Post date:** [June 25, 2010, 12:17am UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/11 "2010-06-25T00:17:58Z")
> [@Really\_Not\_All\_That\_Bright](#): > > I thought diesel engines used fuel as lubricant. You are thinking of single stroke engines. ---
**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\ **Post date:** [June 25, 2010, 12:53am UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/12 "2010-06-25T00:53:24Z")
> [@Baracus](#): > > You are thinking of single stroke engines. I am sure you mean 2 stroke engines. 😉 ---
**Author:** ![Baracus](https://avatars.discourse-cdn.com/v4/letter/b/2bfe46/32.png) [@Baracus](https://boards.straightdope.com/u/Baracus)\ **Post date:** [June 25, 2010, 1:15am UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/13 "2010-06-25T01:15:57Z")
> [@ghardester](#): > > I am sure you mean 2 stroke engines. 😉 I knew something didn’t sound right. ---
**Author:** ![SanDiegoTim](https://avatars.discourse-cdn.com/v4/letter/s/85e7bf/32.png) [@SanDiegoTim](https://boards.straightdope.com/u/SanDiegoTim)\ **Post date:** [June 25, 2010, 2:52am UTC](https://boards.straightdope.com/t/high-mileage-motor-oil-for-older-cars/544282/14 "2010-06-25T02:52:38Z")
For this conversation I define “older” as any overhead valve engine with traditional hydraulic or solid lfters ( vs. those of a roller variety). Perhaps someone can date the general use of roller lifters. I’m guessing mid 1980’s.