# Oil viscosity 5W30 **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [May 1, 2023, 5:13pm UTC](https://community.cartalk.com/t/oil-viscosity-5w30/190369 "2023-05-01T17:13:13Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![melott](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/melott/32/10827_2.png) [@melott](https://community.cartalk.com/u/melott)\ **Post date:** [May 1, 2023, 5:13pm UTC](https://community.cartalk.com/t/oil-viscosity-5w30/190369/1 "2023-05-01T17:13:13Z")
My lawn mower Briggs engine calls for 30W oil. I have used 10W30 with no problem. I have a leftover bottle of 5W30 that fits no car I own now. Would it be OK for the lawn mower? ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [May 1, 2023, 5:18pm UTC](https://community.cartalk.com/t/oil-viscosity-5w30/190369/2 "2023-05-01T17:18:48Z")
> [@melott](#): > > Would it be OK for the lawn mower? Sure! Once the engine gets hot enough the 5W30 oil has the same viscosity as the straight 30 weight oil. Tester ---
**Author:** ![melott](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/melott/32/10827_2.png) [@melott](https://community.cartalk.com/u/melott)\ **Post date:** [May 1, 2023, 5:21pm UTC](https://community.cartalk.com/t/oil-viscosity-5w30/190369/3 "2023-05-01T17:21:40Z")
thanks for the helpful, non-snarky reply. ---
**Author:** ![keith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/keith/32/5518_2.png) [@keith](https://community.cartalk.com/u/keith)\ **Post date:** [May 1, 2023, 5:29pm UTC](https://community.cartalk.com/t/oil-viscosity-5w30/190369/4 "2023-05-01T17:29:16Z")
In addition to agreeing with @Tester, I personally use 5W30 in a 1997 model B&S engine that has had a LOT of use. No problems. ---
**Author:** ![Triedaq](https://avatars.discourse-cdn.com/v4/letter/t/65b543/32.png) [@Triedaq](https://community.cartalk.com/u/Triedaq)\ **Post date:** [May 1, 2023, 5:55pm UTC](https://community.cartalk.com/t/oil-viscosity-5w30/190369/5 "2023-05-01T17:55:47Z")
Is the 5W-30 oil you are going to use synthetic? I had an old mower that the manual called for 30 viscosity high detergent. I noticed that 10W-30 synthetic oil was only $1 more than straight 30 weight. I took a chance and spent my Social Security check on the more expensive synthetic oil. The mower had been burning oil so badly that I fogged for mosquitoes as I mowed. I wore a face mask when I mowed and this was before COVID. The 10W-30 synthetic cut the oil consumption by 80%. I no longer needed to wear a face mask when I mowed and only wear the face mask when I go to the bank to get cash. I got three more years use from that mower. If your mower isn’t using oil, it won’t matter whether the 5W-30 is synthetic or not synthetic. It won’t hurt your mower and might even be helpful. I am now using my backup mower that I bought in 1988. It has a Tecumseh engine. I use whatever oil I have around. When I changed oil for the mowing season, I had some 30 weight heavy detergent. It didn’t completely fill the oil sump, so I topped it off with 10W-30 full synthetic I had. I have used the mower about 8 hours this session and the oil level has remained constant. As long as the upper number is 30 or higher on multi-viscosity oil, you will be fine. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [May 1, 2023, 6:20pm UTC](https://community.cartalk.com/t/oil-viscosity-5w30/190369/6 "2023-05-01T18:20:03Z")
I used to run all my Briggs engines on 5W30 synthetic because I used some in the winter months and I had a lot of that grade around the house. It took DECADES for the Briggs and Stratton engineers to finally accept multi-weight oils. ---
**Author:** ![melott](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/melott/32/10827_2.png) [@melott](https://community.cartalk.com/u/melott)\ **Post date:** [May 1, 2023, 6:59pm UTC](https://community.cartalk.com/t/oil-viscosity-5w30/190369/7 "2023-05-01T18:59:15Z")
the jug in question is 5W30 dino, but I plan to buy 10W30 syn for it in the future. Little or no smoke despite 20 yr age. ---
**Author:** ![bing](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bing/32/4619_2.png) [@bing](https://community.cartalk.com/u/bing)\ **Post date:** [May 1, 2023, 7:45pm UTC](https://community.cartalk.com/t/oil-viscosity-5w30/190369/8 "2023-05-01T19:45:11Z")
I use 5w30 in all my small engines, winter or summer, but I use synthetic. That is according to the revised Briggs recommendations. I guess I wouldn’t worry about it but I have recycled unused oil that I don’t use anymore.