2005 Prius , 58K miles i been reading that with 5W/30 energy conserving oil (synthetic?) you only need to change the oil 7500-10000 miles... i have been doing it every 4-5K. since the "maint. req" light comes on at that point. am I doing something unnecessary? (i only paied $1 / qt, for 5 qt. ) and $5 for the L4477 filter. so it's not expensive at all. also besides the oil change, replacing my air and cabin filter, is there anything else I can replace myself on this car?
At $1/quart the oil isn't synthetic. Synthetics cost $5 to $6/quart. Mobil-1 0-30 at Costco is ~$30/6 quarts in a box. How long will yours last compared to a quality synthetic? I have NO idea Your car will be out of warranty (engine, drive train, etc - NOT the Hybrid components) at 60K. The only way to know for sure if you can extend beyond the 5,000 mile interval is to have a Used Oil Analysis done (I and many others here use Blackstone - costs about $20). There is no way to know how your driving is wearing the oil compared to any of the rest of us. The safest thing would be to change it at 60K (presuming the last change was at 55K) and have it analyzed. Blackstone will give you a nice report (search for Blackstone on this site and you can see some) with a suggestion of how long you can go until the next change. Since I started using Mobil-1 at the first oil change (5K), I went to 7,400 miles (62,470 on the engine) because all other Mobil-1 reports I saw showed there was a LOT of life left at 5,000 and plenty at 10K. Mine came back fine, they suggested going to 8K. Heck with that, my numbers were good so I went to 10K but never got around to sending it in. Planned to do it at the next 10K but didn't get to it for almost 2 weeks after, at 11,600. Report looks good, they suggest going to 13K between changes for my car. As usual, Your Mileage May Vary, especially since you are not using the same oil or filter (Prius OEM even other that at Toyota is ~$4).
cool thanks for the info. i thought the service was too cheap, with regular oil the car is running fine, I average about 52-53mpg for the last 2 years. didn't notice anything bad on the performance part.
For changing the oil every 5K miles, $1 per quart oil is probably fine. Yes, regular maintenance on a Prius is pretty cheap. Start by reading the Owner's Manual and the Scheduled Maintenance Guide.
Use between 3.0 to 3.5 quarts for your refill after oil and filter change or you might end up overfull. Toyota's 3.9 quart fill results in about a 1/4 quart overfill on the dipstick indication.
the maint req lite came on a few days ago for the 45K oil change. i pulled the dip stick and noticed that the oil looks like new/clean oil after 5K miles. no apparant signs that it's been in the crankcase for the last 5k miles. it got me wondering the same question as the title of this thread...by averaging 49.5mpg, the engine barely runs. so then why is it necessary to change the oil when it looks clean and new? well...i went to Pepboys and got this week's $9.99 special (5 qts and a filter). i'll use that today, but still wonder if it's necessary.
What oil had you been using? In the past I've used Castrol GTX 5W-30 and it is quite dark after 5K miles. When I changed to full-synthetic oil I also moved to 7.5K mile change intervals. Currently I'm using Toyota 0W-20 synthetic oil and it is getting darker over time, perhaps not at the same rate as mineral oil.
