Cured the oil consumption problem on my 03 Q45

[TOTitan]

My wifes 03 Q45 has been using one quart every 1500 miles for years. Four weeks ago I decided to try using 10w40 dino oil instead of the 10w30 synthetic that I had been using since we bought the car in 07. She has now driven the car almost 3000 miles since I switched oils, and amazingly the oil is down just half a quart. With the synthetic it would have used two quarts in the same number of miles. I thought Id pass this on since I know that Im not the only one thats been frustrated by their Q's oil consumption problem.

[sprocketser]

A good thing to know , thanx

[djwarner]

Thanks for the heads up. Mine only consumes 2 quarts between 7.5K mile oil changes.

[Q451990]

It would be interesting to see if the same weight of a synthetic would give you the same results.

Heath

[TOTitan]

It would be interesting to see if the same weight of a synthetic would give you the same results.

Heath

I tried that first before abandoning synthetic. It made no difference.

[GSUjinih]

Notice any change in gas mileage?

[TOTitan]

Notice any change in gas mileage?

I have not noticed but it never has been able to average more than 20.1 mpg. The combination of a low rear gearset and being limited to a 5 speed auto really keeps these cars from achieving good mpg numbers.

[GSUjinih]

I would not mind an extra two gears myself. However I can not complain too much as I have been averaging 22-23.6 MPG with 60% highway and 40% city driving with 89 octane fuel.

[qship96]

I would not mind an extra two gears myself. However I can not complain too much as I have been averaging 22-23.6 MPG with 60% highway and 40% city driving with 89 octane fuel.

Might want to read your owners manual regarding the minimum required octane level for your car. Hint, 89 is NOT it.

[TOTitan]

I would not mind an extra two gears myself. However I can not complain too much as I have been averaging 22-23.6 MPG with 60% highway and 40% city driving with 89 octane fuel.

Low 20's still sucks compared to my new VW Sportwagon TDI that refuses to get less than 36 mpg no matter how aggressive I drive it. When I force myself to slow down it gets low to mid 40's, and at only 4500 miles its not even close to being broken in yet.

[groma]

[GSUjinih]

I would not mind an extra two gears myself. However I can not complain too much as I have been averaging 22-23.6 MPG with 60% highway and 40% city driving with 89 octane fuel.

Might want to read your owners manual regarding the minimum required octane level for your car. Hint, 89 is NOT it.

You are right and I did read my owner's ,manual; it is not 89 but 87! My 1994 Owner's manual states on the last page that 87 AKI can by used temporarily used. These cars have knock sensors and will retard timing if there is knock. My 240sx recommends 91 octane too, but has ran fine for over a decade on mainly 87 octane. For my daily commute I am usually under half throttle (with 90% of torque at 2000 rpm), so that extra octane is not needed for the type of driving I typically do.

[Towncivilian]

Have you changed the PCV valve? A clogged or otherwise nonfunctional PCV system can cause oil consumption.

[BadQ45t]

Someone gets over 20 in a 94', I always am amazed by that. I had 92 that only got 19 on the freeway, but not here to call anyone out. WRT to lower grade, if this is a car you drive to and from work and you don't want to still have in the garage 10 years from now, go for it. But using lower grade is harder on the car.

[GSUjinih]

Not sure why you are so amazed by getting over 20 mpg with a Q. The new fuel economy standards rates the Q45 at 20 mpg on the highway and the old rating was 23 mpg. My 240SX is rated under 30 mpg highway, but I consistently get at or above 30 mpg even with some city driving. It is all about driving technique. If the engine is not knocking, how exactly is lower octane harder on a car? In fact I think lower octane is better in some respects as it decrease the chances for carbon build up. If your philosophy is right about not being on the road 10 years from now, then there would not be so many 1995+ Maximas on the road. A lot of the 3rd/4th/6th owners put the cheapest gas they can find in them! Another car that runs much better off premium but runs fine off regular too.

Now I do admit that if you like full throttle, redline rpm shifts all the time, than premium is the best choice.