Prius 3rd gen 1.8 92k km engine oil and fuel efficiency

[rehanfarhat]

Bought prius 1.8 3rd gen last June from its 1st importer at 84k km. It is 4 grade S Led edition with 67k km mentioned on auction sheet (verified). After buying, changed oil Meguin 5w40 on mechanic recommendation along with genuine air / oil filter and plugs. Operated it till 6000 km and avg was around 16.5 to 17.8 km/L. Recently put 0w20 liqui moly semi synthetic and ran for 270km. I m getting 13.6 to 14.7 km/L avg right now. I live in Karachi where weather is extremely hot these days (39-42 C). Question is why half of the people recommend 5w40 for my prius and rest day to use 0w20 till 150k km (some even say 5w20). Prius manual says 0w20 recommended but people argue about hot weather of Karachi. My research suggests that 0 means 0 F = - 14C which will never happen in karachi. The second number after the "W" indicates the oil's viscosity measured at 212 degrees Fahrenheit (100 degrees Celsius). This number represents the oil's resistance to thinning at high temperatures. For example, 10W-30 oil will thin out at higher temperatures faster than 10W-40 will. Kindly explain and help. Karachi responses will be better as I live in Karachi where temp vary from 10C to 43C. AC air filters oil filters were changed at the time of putting liqui molly (1 week ago). Plugs are just like new. Hybrid battery fan was cleaned 20 days ago. No check light or other error.

[hash4u]

All newer hybrids run on 0 20
Or 0 16
Doesn't matter even if u r in sukkur or sibi even

[haseeb.basharat]

Exactly engine optimal operating temperature is around 90 degrees so it doesn't matter. 0w20 or 5w20 are best suited for it. For OP get oil from official website of zic.

[anon35615524]

Brother as per https://toyota.jp/pages/contents/prius/004_p_007/pdf/spec/prius_201308.pdf (this is the latest, revised owners / users manual for your ride, i.e. 3rd generation Prius), recommended engine grades for your ride are: 0w-20, 5w-20, 5w-30, and at max. 10w-30.

If you are a bit sceptical for 0w-20, then you can choose between 5w-20 and at max. 5w-30, and then stick with it (both of these are recommended for your ride).

Do not worry about hot weather conditions of Karachi / Sindh, etc.

Just ensure that engine oil is fully synthetic, 100% genuine and original, from some reputed brand, and meeting latest API SN / SN Plus criteria (with RC: Resource Conserving), and / or ILSAC GF-5.

Let me share the pics from your reference / related manual. They will speak for themselves (regarding fuel tank capacity in dry fill condition, engine oil quantity reqd. with / without oil filter change, engine oil grades, etc.):

[rehanfarhat]

This is quite helpful. Specially JDM Manual screen shots. Right now problem is that I am getting avg 13.8 to 14.5 (after oil change it has run for 240km). Last oil was giving me 16.4 in summer *trip B 1100 km) and 17.6 (Trip A 6100 km) in Winter. Liqui Moly guy told me that after pouring 0W20, you car will give 20-21 kmpl which seems a joke. Hybrid Fan and batteries are good as per my scanner guy. Whats the avg you guys in Khi are getting. Pl mention mfg year, mileage, oil.

[rehanfarhat]

Update: it's 3500km run and avg is 16.1 kmpl. Disappointed as the same can b obtained from 5w20 at half price oil.

[rehanfarhat]

Update 2022: I was continuously using 0w20 till 2021 and in 2022, I shifted to 5W30 as car has crossed 130k ODO. The average in winter is still 19 and in summer, it fells down to 17 (same pattern for many years). I use power mode mostly but drive with light foot.