fla350

Does anyone know if lexus uses the fully synthetic oil for our cars douring service. Also what weight in oil should i use for my is 350?

dshahs420

No Lexus doesnt use synthetic oil unless you specify synthetic, which they will charge more. You can use 5w30 or even 5w20 in your car.

Gernby

iTrader: (1)

Each dealer will probably have different suppliers and oil change policies.

lobuxracer

iTrader: (2)

The current TSB says to use ILSAC GF-4 5w-20 in the 2GR and 4GR engines. It also says you can run 5w-30 in a pinch but should change back to the recommended oil at the next change.

Gernby

iTrader: (1)

I wonder why they changed the recommendation? The owner's manual recommends 5W-30 for all temperature ranges, but says high speed / high load scenarios may warrant heavier weights.

BTW, I'm not familiar with the engine codes. Is 2GR = 250 and 4GR = 350?

menech

close, its reversed


For the United States, three IS models are sold by Lexus:

IS 250 - 2.5 L V6, 204 hp (152 kW), Rear wheel drive
IS 250 AWD - 2.5 L 4GR-FSE V6 with all wheel drive, 204 hp (152 kW)
IS 350 - 3.5 L 2GR-FSE V6, 306 hp (228 kW), Rear wheel drive


http://en.wikipedia.org/wiki/Lexus_IS

Gernby

iTrader: (1)

I just remembered that my UOA from Blackstone Labs noted that the sample oil (factory fill) was probably a 5W-20. I also just realized that my switch to 5W-30 last week might be why my AVG MPG has been significantly lower for the last week. I was easily maintaining over 20 MPG (indicated) before the oil change, but I'm not able to break 19 MPG now.

lobuxracer

iTrader: (2)

It certainly could have something to do with it. Usually it's not so dramatic though. Just a few percentage points, and 20 weight vs. 30 weight isn't a huge change. The previous TSB did say 5w-30, but it's rescinded now.

Gernby

iTrader: (1)

I wouldn't have expected a significant change, but I've been brainstorming for days about why I've noticed such a change. I figured I was just driving differently, so I reset the AVG MPG guage, and have been driving like a granny for 2 days, but can't maintain even 19 MPG. Even when I was driving agressively, I got better indicated mileage than this.

socalJD

I agree w/Lobux, simply changing from 5-20 to 5-30 should not equate to >1 mpg difference. First, don't trust the trip computer, you need to compare manually calculated mpg figures from before/after the oil change. Hell, my actual figures are +/- 1 mpg off from computer. Check your tire pressure, make sure you're at rec settings, the weather may have affected prior settings. Speaking about weather, have you been running the AC more lately than before ? All things being equal, I would expect apprx .5 mpg difference by going 5-20 to 5-30 . . .

Gernby

iTrader: (1)

I wouldn't have expected such a change either, but my tire pressures are closely monitored, my local weather hasn't changed (unfortunately -- > 100 and no rain in a month), and I have a pretty set number of places I drive (without traffic).

Regarding the acuracy of the computer, I think the computer is going to be more consistent than the manual method even if it is less acurate, unless you use the same pump to refill your tank every time

jezza

The factory fill doubtfully started out life as a 5w20. What most likely occured was that throughout break-in the 5w30 sheared down to something closer to a 5w20. Hardly surprising given the rigors of engine break-in.

You won't notice a difference in MPG going from a 5w20 to a 5w30 regardless. There are also so many other variables, the most difficult to control with any type of repeatability being your right foot.

Gernby

iTrader: (1)

I guess you should sell your knowledge of oil to Blackstone, since they knew it was an unknown factory fill / break-in oil with 5K on it, and still said it was probably 5W-20.

Gernby

iTrader: (1)

BTW, are you unable to intentionally drive like a granny for 75 miles? I think I am able. I'm still not saying that it is due to the oil, but SOMETHING happened within a couple days of me changing my oil last week that is costing me ~2 MPG.

lobuxracer

iTrader: (2)

Did you clean and re-oil your K&N? If you did, you might want to get some contact cleaner and shoot the hot wire in the MAF (very, very, carefully!) to remove any oil that might have got on it from the filter.

OR, did you buy gas from a place that laces it with alchohol? You will always get less mileage from a gasoline/alcohol mix. It has significantly lower specific heat.