A lot of people ask about using 5w30 instead of their usual 5w20 or visa versa. So, here are some of the things that might happen if you use a motor oil that is different than the oil the manufacturer recommends for your car or your mechanic recommends for the local weather in San Jose, CA.

Putting the Wrong Motor Oil in Your Car

There are a few different things that could happen when you switch motors oils to one that isn’t recommended for your car or where you live.

Leaking Motor Oil

If your car is well broken in using regular motor oil and you switch the oil to synthetic, then you’ll probably get synthetic oil leaking out of your engine. You’ll either have to keep refilling your oil or switch it back to regular motor oil. Switching to synthetic should be done in the 1st 10,000 miles.

Burning Oil Smell

If your motor oil is not made for high enough engine heat, you might smell the sign of oil breaking down in the extreme heat. This can be serious as your engine’s parts will no longer be properly lubricated.

Low Gas Mileage

If your oil is too thick for weather conditions in the Bay Area then your engine needs to work harder. This means your miles per gallon will decrease. If you’re wondering why suddenly your mileage dropped, that’s why.


When your new oil is too thin, you’ll start hearing an engine ticking sound, especially when you start it up. What you’re hearing are engine parts banging a little bit because they are not lubricated well enough, and that’s not really a good thing long term.

Mixing Oil Brands

Mixing brands isn’t the best practice, as you should stick with one or the other to get a brand’s benefit. But mixing them shouldn’t cause any harm.

Get a Deal on an Oil Change

Bring your car into A1 Performance Auto Repair European Specialists for your next oil change. Check our Deals Page first to snag a discount.

Subscribe To Our Newsletter

Subscribe To Our Newsletter

Join our newsletter mailing list to receive giveway drawings, coupons and deals.

You have Successfully Subscribed!