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Conventional to Synthetic after 7 years?

I have a 2010 Caravan I purchased maybe 7 years ago. I’ve always taken my oil to be changed and always used conventional since there are pretty good deals to be had where I live.
I’ve been feeling mechanically included lately and will probably start doing it myself. I remember a long time ago reading that you shouldn’t switch from conventional to synthetic because it could cause problems. I’ve also read that synthetic oils have changed and that’s not the case anymore. With Wally selling synthetic oil so cheap, it wouldn’t be much of a difference to go with synthetic.

Is there any harm in changing to synthetic after using conventional motor oil for the past 7 years?

That old chestnut has been proven to be untrue.

The only “harm” will be to your wallet because your engine does not require synthetic oil, and you are unlikely to experience any benefits from the switch. However, if you live in an area where winter temps plummet to extremely low levels, you would likely experience easier starting when it is really cold.


You can switch if you want to, but the mineral oil you use now is fine. Just change it according to Dodge recommendations. If you change, make sure to use the same multi-viscosity grade you use now. If you can’t get the same grade, don’t change.


In other word’s if it ain’t broke don’t fix it.


Lets see , you want to change your own oil . If you don’t have them you will need ramps or a floor jack . Jack stands for safety while you are under the vehicle . How much trouble will it be to dispose of the used oil properly ?
The place I use also has a wash for the same price and for another 10.00 tire rotation . Spending money for all that stuff just to change my own oil is not worth it.

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Interesting! Thanks for your answers. I guess the marketing got me to thinking that synthetic offered some benefits, and goodness they push it at those oil change places! Good to know… I’ll use my mechanical inclinations elsewhere. With $25 10-minute oil change centers around here, it’s worth the few extra dollars to have someone else change the oil rather than getting under the car and then having to deal with recycling the oil after.

Thank you!

I’ve been doing a bunch of work on my own vehicle – I already have all the tools, ramps, wheel chocks, floor jacks, jack stands, etc…

BUT if synthetic offers no benefits, I totally agree with you – for the extra $7 dollars, I’ll let someone else deal with oil changes. I have other stuff I need to work on that would save me way more in labor charges!

We have a bunch of 10 minute oil change places around here that cost $25 with coupons online. Definitely no point in getting dirty and dealing with the dealing with recycling of the used oil.

I REALLY hope that you are not referring to Jiffy Lube and its clones, because the error rate at those places is extremely high, and the amount of damage that they are known to cause can be very expensive for the hapless car owner. Their business model includes the following practices:

Hire inexperienced people, and give them truly minimal training
Push through as many cars per hour as possible, even if the poorly-trained employees are not up to that pace
Use the cheapest (garbage) “white box” filters–made in China
Try to “upsell” customers by suggesting synthetic oil when it isn’t needed, and/or a better grade of filter, and/or trans fluid changes that their employees are not qualified to perform.

Your best bet if you want to avoid damage to your (pick one or more) engine, transmission, cooling system, brake hydraulic system is to have your oil changes done by a local, independent mechanic.


I used to use a local Jiffy Lube for oil changes on my cars using mineral oil. When I bought my 2018 Accord 2.4L, I found that they wanted $90 for the full service instead of the $40 with mineral oil. Synthetic oil doesn’t cost $50 more, and I stopped using them. This particular store does good work, but the price is outrageous. I use my repair shop now at a relative bargain price of $60.

i would prefer syn oil for cold climates

The whole point of changing your own oil isn’t to save money. Even at DIY prices, it’s not much cheaper than using a Jiffy Lube-type place. The point is that you will do the job better than they would. As a DIYer, you will use a higher-quality filter, higher-quality oil, and avoid the risk of damage from haste and inexperience that these quick-lube places are known for.


I’m about convenience and efficiency … I have a tight schedule so it’s possible for me to make mistakes as well (which I have). That was the whole point of my post. If synthetic oil poses a benefit and I’m paying the same and using the same amount of time as conventional, then I’m all for it. If there’s no benefit, at the risk of ruining my coolant and brake system… and transmission and whatever else was suggested by going to a quick lube place … I’m all for that. I know how to look for leaks and check for puddles … I drive a vehicle I bought 7 years ago and have replaced countless items myself.

That said, if I can buy better oil than they use (which was the synthetic vs conventional question), knowing I change my oil ever 3000 miles, and still somehow come out on top, I would do it myself. But if synthetic offers me no benefits, there’s no reason to believe that the local jiffy lube guys can’t unscrew an oil pan drain plug and a filter and replace them both, pump 5 qts of oil into my engine, and get me moving on with my life. If they didn’t screw the drain plug or filter in properly, I’ll quickly notice it and fix it.

I too have been concerned about switching my Pontiac to synthetic so hope the boys above are correct. The thing is, I always used Mobil conventional but it is no longer on the shelf and has been converted to synthetic blend. The store assured me it was the same but still I’m a little concerned about leaks developing. I picked up a 5 qt jug for about $14 compared to the synthetic I also picked up for $30. So can’t be much of a blend anyway.

So yeah, I’d go with either conventional still or the new blend. And I never put my cars on ramps to change oil. The one is high enough to crawl under and the other I just jack up a little to get more clearance. 30 minute job and it’s done right and on my schedule.

But do you know what oil iffy lube is putting in your car as you can not be by the car while they are doing it?

I remember back in the early 1950s when heavy detergent oil was new. Sometimes when a person as switched from non detergent to detergent, problems sometimes occurred. My dad had a 1949 Dodge. When he switched to detergent oil, oil consumption shot up immensely. It started using a quart every 300 miles. I think some of the problems of switching from non detergent to detergent has caused some of us old timers to be reluctant to switch from non synthetic oil to synthetic oil.
I had a good experience making the switch from regular 30 weight to 10W-30 synthetic in my old push mower. The mower burned so much oil that I wore a face mask while mowing. When I went to buy oil at my local Rural King farm store, the 30 weight heavy detergent regular oil in the house brand was $1.79 a quart. Full.synthetic 10W-30 was $2.79 a quart. I decided to gamble a dollar and buy the full synthetic. Over the course of the sesson, the oil consumption decreased to the point where I didn’t have to add oil. I have gotten two more seasons out of the.mower. This fall, I did notice the oil consumption increasing. However, to get three seasons out of a mower that I was ready to junk for an extra bm$1 for the synthetic oil paid big dividends for me.
If an engine is doing fine on non- synthetic, it probably isn’t worth the extra cost. However, if your engine is using oil, switching to synthetic may be helpful.

… or not…
I experimented with a lot of oils for my friend’s oil-burning 2008 Rav-4, and there was no difference in oil consumption when I switched to Mobil-1. The only difference of any significance was when I switched to conventional Pennzoil. It still consumes oil, but the consumption rate is slower with conventional Pennzoil.

No, I can’t explain it.

Every 3000 miles might be over kill but that is your choice . What does your manual call for ? I think 5000 miles or 6 months would be sufficient .

@VDCdriver Maybe I was just lucky with my mower engine. It did start using a little oil last fall when I was mulching leaves. If the mower really starts burning oil this coming spring, I will give up and buy a new mower. However, the extra $1 I spent at the beginning of each season for the synthetic oil when I changed the oil to prepare the mower for the season was money well spent.

I go to take 5. You never get out of the car there, you’re in it watching them the whole time (except the guy underneath the car). They always date and initial the oil filter.

Way back when synthetics first hit the market, and I believe you were probably around then too, the seal swell rates between conventional and sythetics were dramatically different. Switching from long use of conventional to synthetic could result in more seeping or leaks from seals. They quickly corrected that and ever since you can go back and forth without concern. The OP did acknowledge reading about this “a long time ago”.

I had an unusual experience with one of my motorcycles I proved wasn’t a fluke by going back and forth and seeing the same results. The gearbox is notoriously noisy and clashes a bit on conventional oil. So reading about others that switched to synthetic and got it to perform more smoothly and less noise, I tried it. The good news is it did make vast improvement but soon discovered oil was being consumed at an alarming rate. Switching back and forth produced repeatable results.