jmg330

iTrader: (3)

i am a new owner my wife drives the rx300 she picks the kids up from school

etc.. all CITY miles - and all i get is 15mpg ? its the 2wd model with only 67k

miles i thought city MPG = 17 mpg ? she drives with the a/c all the time is

this common city MPG? i drove it on the HWY and it shows 22-23 mpg on the display

i know i get good HWY mpg but city blows on this LEX. she is very nice

looking i put some 18" OEM lexus 330 wheels -

2001 Lexus rx300 - 67k miles

18 oem rx330 rims

lexina

It is very common to get 15mpg with ac in city.

hypervish

Does your wife wait for the kids outside of school while idling? If so, that's a major hit on mpg's. Running the A/C all the time in the city, will also kill the mpg's. Is there traffic, I'd imagine not, as it's Texas? But I've never been there, so I don't know.

How's the air filter? What octane fuel do you run? Have you checked the tire pressure?

Carver

Nope, nothing but wide open spaces as far as the eye can see. Seeing another car is so rare we usually flash our headlights at each other and if we see a Lexus we honk and wave and if it's another RX we stop and get a beer.

jmg330

iTrader: (3)

should i use 93 oct. will that help my MPG in the city driving?

so when the Govt. put the MPG posting of 17 MPG "city' did they run it with the AC off ?

rx300mm

I have noticed for sure more miles per gallon when using 93 octane, the reason why I use regular is because in Ontario we 13+ cents more per litre (approx 50 cents a gallon more) for 93 octane .. so I am happy with 87 octane.

iolmaster

iTrader: (1)

Using 93 octane will not increase your gas mileage. Not just my opinion. No science to support that statement. I know many think it is true. 93 octane actually detonates more slowly than 83. That is why higher compression engines need it. It is not more powerful.

carguy07

It's more powerful if the timing is advanced because it is not detonating.

iolmaster

iTrader: (1)

All you are saying is, that if you use 87 in an engine that is designed for 93 you will not get as much power because of pre detonation of the 87. Agreed, that is not the situation described.

sktn77a

iTrader: (2)

The RX 300 is designed to use premium gas (91-93 octane). If you use regular gas (87 octane) in the RX300, the ECU will sense preignition (detonation) and will retard the timing to prevent this. The performance and gas mileage will go down a bit (1-3 mpg in most higher performance cars).

hypervish

x2. I always use 93 octane. It takes about 30-40 for the system to "learn" what octane your using, and it will then make the necessary changes.

iolmaster

iTrader: (1)

Please read page 264 of the manual. It states octane rating of 87. When I first got my 2000 ES300 and then the 2000 RX300 I had a number of conversations with Lexus corporate and local service advisers. There is complete agreement that this engine does not need anything above 87 octane. I had a number of dealerships indicate they only put regular in these engines on the lot. This engine is anything but high performance.

carguy07

Yep, manual calls for 87 minimum. I run it or 89 most of the time and have never heard it knock or ping once. I do think there is a little power to be gained with higher octane gas when the timing advances. Might not mean more gas mileage though. Most people are not pulling a load that makes much difference in daily driving. If I was going to tow something (crazy to tow much with this car) I would put higher octane gas in it.

rx300mm

I disagree with you for RX300, my manual and the tank lid recommends regular gas (87 octane).

ausbun

I usually put 87 octane in my wife's RX300, unless it's at a no-name station. I can tell a difference in the performance between the no-name regular and the national-brand regular.