pjp900

Recently i changed my oil and put in 10w40 i know that the type of oil should be 5w30 but my motor has low oil pressure so i figured it was worth the try. I have now a half a tank of gas with 250 miles on the dash, never before have i had this kind of gas mileage usually it was around 150 at a half a tank. Does this make any sense to anyone? any help would be great.

maxgtr2000

iTrader: (29)

You still have half a tank to go before you get happy. I've had excellent gas mileage at half a tank only to be let down by the mileage of the other half.

Zero9890

Same thing has happend to me

Chief Brody

iTrader: (2)

Doesn't make sense to me. Like the owner's manual says, for better fuel economy use 5w 30. Don't think viscosity should make that big of a difference in fuel econ. You do a tune up at the time you changed your oil? Don't rely on the fuel gauge either, not very accurate.

BTW I think 10w30 is the maximum recommend viscosity.

tslrock514

definatly the same thing here i get great gas till about 3/4 tank then it drops a whole **** load faster!

Bobo

Fill the car up and divide the miles driven by the gallons consumed and be prepared for disappointment.

pjp900

yeah i know that it sounds crazy, i'll finish the tank of gas and then post my mileage, then we can discuss the crazyness

oVeRdOsE

is it a good idea to put synthec oil , like 5W 50?? Someone told me that it could be possible to blow out my engine if I put syntec, is that true??

Thanks

Bobo

Could you please elaborate on how the use of synthetic oil will blow your engine? That is utter nonsense!

What year car do you have? How long have you owned it? What is the mileage?
Do you have the maintenance history for the car?

oVeRdOsE

Allright, the guy is a mecanic , he said that the synthec is too viscous, and if your engine NEVER use this type of oil, the synthec can go in your valves, or some thing like that and blow the motor head. I dont really belive him , but he seem to know everything, he show me how its can possible , he go get the other mecanics guys, he was sure of that! he said DONT PuT SYNTEC IN a 150 000 km engine!!!
Oh, by the way it was in a canadien tire , for canadian... lol

pjp900

synthetic oil does not blow an engine, it will only leak out of gaskets more due to its chemical make up (smaller molecules) i have a 97 max 175,000 miles. so i naturally have low oil pressure which would result in "more" friction so im really confused

nismology

iTrader: (8)

Low oil pressure has NOTHING to do with oil viscosity and EVERYTHING to do with not enough oil in the engine. You have an oil leak somewhere and the oil pressure light will come on again sometime down the line. BTW, when the low oil pressure light comes on, there is less than 1 quart of oil in the engine.

oVeRdOsE

Yeah , thats make sens , but what can happen if you put like 5w 50 or 20w50 in a 96 max 150 000 km??

pjp900

i actually have an oil pressure guage so thats how i know that my oil pressure drops, and has been increased when i put in 10w40 oil. as for leaks, nope dont have them, i changed both valve cover gaskets and oil pan gaskets already. my only other option is oil pump and man\crank bearings. also i think i would know if i didnt have enough oil in there. thanks though!

pjp900

ok so i just finished my tank of gas with a mileage of 390. all my normal highway driving. i have never seen such a high number. 320 was the norm. im not complaining on my newly found gas mileage but im just really confused how a higher weight oil did this to my car.

ewuzh

iTrader: (20)

How many gallons did you fill at the gas station?

Gas mileage is miles/gallons hence mpg.

pjp900

i put in 15 gallons exactly.

Bobo

So you got 26 mpg. That's not too bad for a combination of city/highway driving. You haven't stated what kind of driving you did this tank on and what speed you were going. Fuel economy does improve as you get into warmer weather and stop using winter gas. I still call BS on the 10W40 oil having anything to do with improved fuel economy.

If it were my car and I only got 320 miles to a tank of gas, I would have figured out the problem a long time ago. The lowest I have ever had in straight city driving is 350 miles and that was with the light on for some time. On the highway I've gotten as high as 550 a couple of times and regularly get 500+ on longer trips driving at 75 mph most of the way.

pjp900

wow i totally wish i got 500 miles to a tank of gas. the gas mileage was on all highway, but all i drive is highway doing an average of 80. as for the type of oil i thought that maybe it had something to do with it but maybe i was wrong

Bobo

If you drove 65 rather than 80 your mileage would improve significantly. I'm not suggesting you do that but at 80 you're sucking gas.

When I say 500+ at 75 mph, there are stretches where I'm driving slower than that, particularly getting out of the city and accessing the freeway, but not faster. It also helps to use cruise control on the highway if the traffic permits.

jp_cout

I got 475 when I went to a trip of mostly highway...I was driving at 90 mph most of the time with a blown MAF...seems that I'm getting great gas mileage..??!! BTW, my MAF is blown so it won't torque as much as it's suppose to do it...600$ CAD for a MAF sensor...is it too much??

thanks!

pjp900

yes that is way to much $. Yeah i guess i can see what your talking about rmurdoch oh well i guess im just going nuts

Bobo

I've been that way for years. Don't worry about it, as it gets worse before it gets better, lol!

Amarao

I've been using full synthetic Valvoline on my max (265,000 miles) doesn't seem to be burning any oil and I'm getting about 450miles per tank, about half city (avg. 40mph) and half highway (avg. 80mph). I'm surprised that a lot of you aren't getting over 400 miles per tank.

Bobo

What kind of octane are you running, Amarao? I believe you can get by on lower at altitude. Also what year is your Maxima? The highest mileage 4th Gen I've noticed until now is a recent post with 261K.

Amarao

85 octane low grade up here, i honestly notice lower mileage with higher octane up here, and sine it's not knocking or pinging I'm not too concerned. It's a 95, never had any engine problems, replaced the transmission 3yrs ago, driveaxles last week. It was burning oil at high rpms but i ran a can of BG 44K through it and it stopped.

ewuzh

iTrader: (20)

Your engine must only be producing 140hp. Doesn't your car feel slow?

Amarao

Doesn't feel slow to me, i suppose i could dyno it, i know a shop in denver with a wheel dyno. How do you figure I'm only producing 140hp? you mean at wheels? I can easily keep up with the V6 Eclipses and the tires chirp at 4500rpm if that helps any.

maximazation

iTrader: (11)

usually you get more miles from the lower half of the tank.

97SEdriver

iTrader: (3)

The low oil pressure can come on for various reasons, low idle for instance, but either way it signifies low oil pressure, not low oil. I am fairly sure I have the idle problem, my oil light was coming on all winter, but that may be because I mix oils. If you do auto-x and especially track events, and I occassionally do both, I normally put in 1-2 quart of 20-50, 1 synthetic blend, 1 or 2 qts 10-40, and maybe some prolong or lucas oil. I have been doing this since I bought my 97se in 99, now I have 145K, and I hit 120mph at 2-3 times per year(on the track, mostly).

Boomersooner85

Ok this is sort of off of the topic but some of the replies can relate to this. I recently had my water pump changed out. Before this though, somehow the water pump just died and water flooded my engine. Well so I get the pump fixed and get the car back but when it's in park, the "Oil" light flickers...and then when I drive it stays off. Does anyone know what's causing this?

killcrap

iTrader: (3)

he is from canada. his odo probablt reads in kms. i have a canadian car and i usually get 600 kms with 16.5 gallons.

so your 390miles would be 627KMs i usually round out to 350 miles every 4 days. from full to almost empty. did that a couple of times just to find out., and now i dont let it get more than 1/4 way empty.