# Synthetic motor oil- worth it for me? **URL:** \ **Category:** Factual Questions\ **Created:** [February 28, 2006, 6:20am UTC](https://boards.straightdope.com/t/synthetic-motor-oil-worth-it-for-me/346425 "2006-02-28T06:20:00Z")\ **Posts on this page:** 9\ **Page:** 3
**Author:** ![Lightray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lightray/32/391_2.png) [@Lightray](https://boards.straightdope.com/u/Lightray)\ **Post date:** [March 3, 2006, 2:30pm UTC](https://boards.straightdope.com/t/synthetic-motor-oil-worth-it-for-me/346425/41 "2006-03-03T14:30:53Z")
Synthetic oils also have fewer additive incompatability issues than “dino oil”. Better compatability with the active additives means you get better performance from your synthetic oil. This is probably not a difference you would see over the short term. > [@Rick](#): > > Mr. Slant has a very good answer. But, **ombre** you might want to cruise over to [this thread\*](http://boards.straightdope.com/sdmb/showthread.php?t=352827&highlight=synthetic+motor) and read posts 19 & 20. Make sure to read the links in post #19. This should help explain why snythetics are needed for some engines. Not going to necro that thread, but I may as well comment on this: > [@Rick](#): > > Here in the US to the best of my knowledge the only oils that meet ACEA A5/B5 are full synthetic oils. The last time I went oil label reading (I told you I lead an exciting life!) no dinosaur based oil met the A5/B5 certification. > So is it the base oil quality or the additive package that makes the oil go from A1/B1 to A5/B5? Beats me, but the only oils you can get on this side of the pond that meet the A5/B5 are synthetic. It’s the additive package (of course, I would say that, wouldn’t I?). Base oils available help with, but do not satisfy, all of the certification requirements. And some times the oil supplier changes their base oil stock, and we need to reformulate the additives so the certification is maintained. ---
**Author:** ![Mr.Slant](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)\ **Post date:** [March 3, 2006, 2:35pm UTC](https://boards.straightdope.com/t/synthetic-motor-oil-worth-it-for-me/346425/42 "2006-03-03T14:35:05Z")
> [@Lightray](#): > > SNIP > It’s the additive package (of course, I would say that, wouldn’t I?). Base oils available help with, but do not satisfy, all of the certification requirements. And some times the oil supplier changes their base oil stock, and we need to reformulate the additives so the certification is maintained. Does that mean I can supply a barrel of Group I base oil and you can give me additives that will let it meet A3? ---
**Author:** ![Lightray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lightray/32/391_2.png) [@Lightray](https://boards.straightdope.com/u/Lightray)\ **Post date:** [March 3, 2006, 3:14pm UTC](https://boards.straightdope.com/t/synthetic-motor-oil-worth-it-for-me/346425/43 "2006-03-03T15:14:57Z")
> [@Mr. Slant](#): > > Does that mean I can supply a barrel of Group I base oil and you can give me additives that will let it meet A3? We do formulate with Group I oils – mostly for low-cost products in Asia and the Middle East. If money is no object and you have a few $MM for a development and engine test program, I’d bet that someone could formulate something close to that requirement using Group I. It would probably be mostly additives (instead of \< 5-10% additives as most motor oils are). Of course, I don’t know anyone who’d’ve actually wasted rig time on testing a Group I for that certification, so this is all hypothetical hand-waving on my part. Much like that question. ---
**Author:** ![Spiff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiff/32/9852_2.png) [@Spiff](https://boards.straightdope.com/u/Spiff)\ **Post date:** [March 3, 2006, 3:20pm UTC](https://boards.straightdope.com/t/synthetic-motor-oil-worth-it-for-me/346425/44 "2006-03-03T15:20:21Z")
> [@Mr. Slant](#): > > Synthetic 0W30 starts nicely at -40 F. > Conventional 0W30 does not exist. > Mobil 1 can survive for extended periods above 300 degrees fahrenheit. > Conventional oil begins failing rather quickly at that point. > Those are the biggest two reasons for synthetic. > Neither applies to 99% of consumers. We don’t get -40 degree F (or -40 degree C for that matter 🙂 ) here very often. But two weeks ago it was -20 degrees F here. (I live in Minnesota.) I decided to put synthetic oil in my '95 Honda Prelude last fall primarily because I have only a 7-8 minute commute to and from work, and that’s way too short for the engine to get really warmed up during our typical winter weather. With 85K miles on the engine, I decided to give it synthetic oil to ease the strain on my engine as it starts up from sub-zero temperatures. Now, I’ll have to decide how long to wait before changing the oil. I’ve pretty much adhered to the 3,000 mile interval with dino oils, but now I’ll try to at least double that. Incidentally, I’m holding off putting synthetic oil in my 2005 model year motorcycle (only has 800 miles on it now) because I’ve heard that synthetic oil slows down the engine break-in period. So, I think I’ll hold off on putting synthetic oil in my dear Thumper\* until about 10K miles. Which will be a LONG time from now, what with just a 7-8 commute (and the bike only gets used in the summer, natch). - A generic name given to any one-cylinder motorcycle. ---
**Author:** ![Anne\_Neville](https://avatars.discourse-cdn.com/v4/letter/a/b9e5f3/32.png) [@Anne\_Neville](https://boards.straightdope.com/u/Anne_Neville)\ **Post date:** [March 3, 2006, 4:45pm UTC](https://boards.straightdope.com/t/synthetic-motor-oil-worth-it-for-me/346425/45 "2006-03-03T16:45:42Z")
> [@Mr. Slant](#): > > Synthetic 0W30 starts nicely at -40 F. _I_ don’t start nicely at -40 F :eek: I’ve been in California for so long (8 years this summer) that +40 F is pushing it… ---
**Author:** ![RogueRacer](https://avatars.discourse-cdn.com/v4/letter/r/7ab992/32.png) [@RogueRacer](https://boards.straightdope.com/u/RogueRacer)\ **Post date:** [March 3, 2006, 7:36pm UTC](https://boards.straightdope.com/t/synthetic-motor-oil-worth-it-for-me/346425/46 "2006-03-03T19:36:48Z")
I’m kind of curious to hear what the experts think of something else that hasn’t been mentioned so far, fuel saturation. I realize that most newer computerized cars aren’t going to run rich with properly functioning sensors. Still, I think it would be a problem with most cars in cold climates during the winter. I know that if you accidentally manage to flood a car, it’s time to change the oil change. This kind of leads to why I don’t use synthetic in my street car. Sure the synthetic holds up better to heat, but I can’t see it helping much with the contaminents. I would rather change the dino-oil at 4-5K than hold off to 10K on synthetic to try to make up for the expense. In regards to the OP, I would just read the owners manual and use what it recommends. Someone mentioned it takes 5w-20. I would keep an eye on what they use at the oil change place. I know the quick lubes around here don’t have that on tap. I would guess bigger cities may be different, but if they’re pumping it in, I would make sure it’s not just 10w-30 or 5w-30. ---
**Author:** ![Mr.Slant](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)\ **Post date:** [March 3, 2006, 11:14pm UTC](https://boards.straightdope.com/t/synthetic-motor-oil-worth-it-for-me/346425/47 "2006-03-03T23:14:30Z")
> [@Spiff](#): > > We don’t get -40 degree F (or -40 degree C for that matter 🙂 ) here very often. > > But two weeks ago it was -20 degrees F here. (I live in Minnesota.) > > I decided to put synthetic oil in my '95 Honda Prelude last fall primarily because I have only a 7-8 minute commute to and from work, and that’s way too short for the engine to get really warmed up during our typical winter weather. > > With 85K miles on the engine, I decided to give it synthetic oil to ease the strain on my engine as it starts up from sub-zero temperatures. > > Now, I’ll have to decide how long to wait before changing the oil. I’ve pretty much adhered to the 3,000 mile interval with dino oils, but now I’ll try to at least double that. > > Incidentally, I’m holding off putting synthetic oil in my 2005 model year motorcycle (only has 800 miles on it now) because I’ve heard that synthetic oil slows down the engine break-in period. > > SNIP If you’re interested in how much synthetics and/or lower viscosity oils can help increase your gas mileage, you can go [here](http://www.iea.org/textbase/work/2005/EnerEffTyre/calwell2.pdf) [1] [PDF] and inspect pages 8-11. By extension, if it’s saving you gas, it’s letting you baby your engine by hitting it with that much less power to get the same speed. The vast majority of Americans with the vast majority of cars and situations can go 6000 miles with no trouble, even on conventional. You _should_ be okay, but your application _might_ wind up with persistent condensation in the oil. I hope you have a once a fortnight trip to granny’s an hour away or somesuch to let you periodically burn off water contamination in the oil. Even with mild abuse, most Honda engines will last longer than their bodies, transmission or owner’s desire to keep driving the same car. Regarding the “break-in” period issue on your motorbike, to the extent that you have a modern engine manufactured with the same kind of processes that most carmakers use, it probably doesn’t matter. To the extent that the engine was built in a shop with processes unchanged since the early 1960s, a break-in period may matter. Disclaimer: read your manual. [1] [http://www.iea.org/textbase/work/2005/EnerEffTyre/calwell2.pdf](http://www.iea.org/textbase/work/2005/EnerEffTyre/calwell2.pdf) ---
**Author:** ![Mr.Slant](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)\ **Post date:** [March 3, 2006, 11:34pm UTC](https://boards.straightdope.com/t/synthetic-motor-oil-worth-it-for-me/346425/48 "2006-03-03T23:34:28Z")
> [@RogueRacer](#): > > I’m kind of curious to hear what the experts think of something else that hasn’t been mentioned so far, fuel saturation. I realize that most newer computerized cars aren’t going to run rich with properly functioning sensors. Still, I think it would be a problem with most cars in cold climates during the winter. I know that if you accidentally manage to flood a car, it’s time to change the oil change. > > SNIP I just went through every single used oil analysis on the Internet for my car’s engine, the 3L Ford Duratec 24V V6. That is 10. (I didn’t search. I keep a spreadsheet, but I’ll probably move my data set to an Access DB before too long.) One sample showed 1.3% gasoline contamination in the oil. One sample showed 0.5% gasoline contamination. The other eight samples showed “below detection threshold” in the nomenclature of the various labs doing the testing, while the labs tend to have a consensus that fuel levels below 2.0% are acceptable. The four Mazdas with the same engine block showed up “below threshold” as well. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [March 4, 2006, 1:30am UTC](https://boards.straightdope.com/t/synthetic-motor-oil-worth-it-for-me/346425/49 "2006-03-04T01:30:33Z")
**Mr. Slant** I suspect that most if not all case of severe fuel contamination do not get analyzed. I mean why bother? The crankcase is reading maybe 1 qt high, and the dipstick smells like the high test pump. You would just be spending money to find out what was already obvious. Getting back to your question **RogueRacer** , I’m out in Sunny California where we keep the snow up in the mountains. We visit it when we want to, we don’t live in it. But with that said I have done lots of new car get ready inspections where the oil was fuel saturated. This was due to it being winter over in Europe, and the cars have been started and stopped lord knows how many times between the end of the assembly line and my stall. Most of these engine starts lasted maybe 30 seconds tops. So how did we treat these engines? Start them up, let them go at a high idle (1500ish) and do the inspection. By the time we finished our inspection he oil would be hot, the gas and condensed water would be burned off, and the engines ran fine. So unless you drive all very short trips and never warm up your engine, I don’t see this as a problem. Of course if you have a sensor go bad that floods the crankcase with gas, that is a different story. [Previous page](https://boards.straightdope.com/t/synthetic-motor-oil-worth-it-for-me/346425.md?page=2)