so i did an oil change from previously valvoline maxlife 10W30 with a FRAM oil filter and went to mobil 1 supersyn (full synthetic) 10W30 with a mobil 1 oil filter, and my mileage has gone way down! I thought it would go up with the change to synthetic....read about someone else who had the same issue, but I can't find the thread to find out what people were saying about it and what happened in the end....

does anyone have the link to the thread that talks about this exact issue with lower mileage going to mobil 1?

why would something like this happen? it is a considerable loss in mileage as well...should i just wait about a 1000 miles or should i just change it back to valvoline or some other oil? should i stay with synthetic at all?

 

Use 5w30 instead. Maximas don't use 10w30. It is too thick.

 

But he lives in a climate where he'll never see freezing temperatures if I'm not mistaken so 10W30 should be fine...

 

http://forums.maxima.org/showthread.php?t=227996

as our moderator bill suggested, FRAM product sucks. you should change to nissan OEM oil filter. FRAM does not filter as good as nissan OEM filter.

my personal experience with mobil 1 supersyn synthetic oil + nisan OEM filter gave me better gas milage, i felt a bit more power, and the engine shifts smoother. you can change out my homepage, page 6. it has my basic maintance information on it. good luck man

false. maxima takes 10W30 as well. since his area is warm all season, 10W-30 won't hurt.

true.

 

btw if your gas milage still suck after you switch to nissan OEM filter, then you should probably check and clean your other engine components. here's some items that you should check it out:

0. do you have any CEL (check engine light)?
1. is your throttle body clean?
2. is your air filter clean?
3. are all 6 of your spark plugs working?
4. is your IAC valve clean?
5. do you push your car hard? (ie. redline every gear)
6. is your engine coolant temperatur sensor working functionally?
7. is your battery keeping up its voltage?

other minor things make affect your gas milage. so keep us posted about your gas milage. post back if you have any more questions and we'll try to help you out.

 

Maybe the synthetic oil is cleaning out the engine and holding lots of junk. Thus its bubricating properties is not as good as it could. Your mileage sould improve after the next oil change. For peace of mind, you can check if the oil is very dirty and change it.

 

this huge mileage drop has come right after the oil change....so i can't be any of the other things suggested above, the oil looks perfect and like it did new...like i said i don't have many miles on it yet so maybe, the synthetic oil and its additives are not "active" yet or something ("grabbing at straws here!") in either case, i have a new air filter, new pcv, new fuel filter, mobil 1 oil filter changed with the oil, spark plugs are new, coolant is new, battery is 1 week old! and IAC is clean as a whistle! i don't push my car, shift just before 3K every gear....because I live in southern california, 5w30 is not neccessary, i have friends who have tried all the different weights and viscosities in their cars and have noticed almost no difference in mileage....don't know why in my case, going from non-synthetic valvoline 10W30 to mobil 1 supersyn 10W30 would make such a dramatic drop in mileage!?!?!? so i kept the same weight and viscocity (sp?) as you can see....but went from a fram to a mobil 1 filter...............can the oil being to high or too low effect mileage....i think my oil is on the high side right now...

 

how much did ur gas mileage drop btw? how significant is it?

 

i think i just found out why my mileage has dropped, my oil level is too high! too much oil would make the engine work too hard and have more resistance...

 

how much oil did u put in?

 

First off all how many miles is on your car?
Second once you use Synthetic, you can't go back it can mess up seals, like oil pan exc. I have been using 10/30 Mobil 1 and now run 15/50. Synthetic 10/30 is thinner than a 10/30 conventional oil base. I would just run 10/30. But when I started to use mobil 1 in my maxima it had 62,000 on it. I bought it in june 2002 with 62,000. So I can't tell you if you get better mileage with conventional oil. Because I use only Mobil 1 But I get 21 thru 26 miles to the gallon and I have a auto. My car has a 117,000 on her now. I replaced the Engine at 113,000 with VQ30 out of a 1999 infiniti, because a timing issue I had with my other motor when I replaced the water pump, basically I have a new motor for nothing but hey I cant complain the new motor has 38,000 when I bought it a couple a months ago now i have 44,000 on the new motor. I'm using 15/50 and I recorded my mileage tonight 6 gallons and I went 145 miles so that meant i got 24.16 MPG so thats great and Im not light on the foot but was mostly highway miles at about anywhere between 70 an 85. A couple of races to. I went a 100 twice. So I can only say that i have no effect with Synthetic. 15/50 is the same as a 10/30 conventional base. Like I said Synthetic is a thinner base but also leaves a thin layer of protection on your internals for like cold start ups. So its great oil but again I need to know how many miles you have on your car cause if you have alot stay with what you have, Max life. It would be a waste to start using syn in a older motor. Just make sure you change your oil every 3000 with conventional oil, with Syn you can go has high as 10,000 I have taken my old engine up to 10,000 and the oil was fine. I have great compression out of each cylinder
out of the old motor. But I also do alot of highway driving so the oil lasts
longer than stop and go. But I would recommend changing syn every 6,000 miles. I hope I been a help.

 

Hey make sure your cars engine is off for about 20 min. Before you check the level. If you check the oil right after you shut down the motor even if you wait five minutes with it off. It will show a very high level. YOU MUST WAIT FOR ABOUT 15 to 20 min. Trust, try it. I had an issue with my uncles 2002.
When it was bought brand new I checked the oil after i turned the engine off and the oil level was very high. So I called the dealer and said the oil is over filled. They told me that the VQ30 and Vq35 will show very high if you don't let it sit for about 15 min to even a half hour, before checking it. So I waited 20 min and guess what it was right at the H mark not over it, so they were right. I know this sounds stupid but its the design that they made for good reason im sure. So try it and tell me what you see. Now when I change my 1996 Maxima's oil I make sure I put 4 and a quarter, quarts of oil. Then I start it and turn it off and wait 20 min. The oil is right were it need to be
Hope this is a help

 

if so, like you said, give it some time to adjust to the new setting and see waz up.

 

Slightly ot here, but what issue did you have with timing after you changed the water pump? I have terrible timing chain noise after my water pump was changed. I'm not quite sure why this is because I also put in Mobil 1 10w30 at the same time. Previously I have been using 5w30 exclusively.

 

maybe your tensioner isn't tight enough, it may need to be readjusted or tightened after the water pump install. check it out

 

Prove it. I thought not. Stop spreading this garbage.

 

Once you use synthetic, you can go back to conventional. I have with no ill effects, and on several vehicles. I went from Mobil 1 5w30 to Castrol GTX 10w30 in my '97 Maxima because I didn't like the high lead and iron in my UOA from the Mobil 1 (not saying Mobil 1 is bad oil, just not for me or my engine). If your car is properly maintained (especially routine OCI's), there shouldn't be an issue. Like 2002 Maxima SE said, stop spreading this garbage.
To those who think they feel more power after an oil change, I guess your butt dyno is super calibrated. Any change in power would be easily within the margin of error of a real dino. I know my butt dyno is not as accurate as a machine.
I also doubt you will see a mileage increase from proper oil changes (proper fill levels) when going from conventional to synthetic of the same grade. There are too many variables that affect mileage that would explain any measurable difference. Manufacturers claim mileage increases based on differences between grades (like a 10w30 to a 5w20) to conform to government regulations. They are measuring mileage in a controlled environment, and spreading the gain over thousands of vehicles. So to them, a 0.1 mpg is significant when factoring in the large number of vehicles (and different models) in their fleet. This is so they can say their fleet of vehicles averages so many mpg (averaging all models together), and meet government requirements for a manufacturer. Oil companies use this to their advantage as marketing hype (and this is between different grades. Try to find a company claiming increased mileage when compared to an oil of the same grade. The FTC would be all over them like they were on Slick 50 and others about their mileage and wear claims). To someone driving on the street, a 0.1 mpg decrease can be accounted for by the time they punched it once to merge on the highway. Or a variance in ambient temp. Or a dirtier air filter. Or slightly more worn plugs. Or the natural decrease of tire pressure when cold or from age. You get the idea.
And can someone explain to me how an engine oil is going to improve shifting? With 18 years experience of working on cars, I've never come across this issue...

Dave

 

Take a Timing light to it. See were it the timing marks are.

 

If the tensioner was bad you would know it. That motor if it is even one tooth off it could cause it to bend valves.

 

I agree with the part where this guy said it shifted smoother, that has to do with the tranny. There is Solenoid packs that control shifting and if motor mounts are good it should shift smoother I just think this guy means his engine is smoother.
I will agree that conventional oil is great if changed within 2,000 thru 3,000 miles. You can sit here and say Mobil one is a waste. But I will tell you it isn't and you will tell me it is. But the true fact here is it is better than conventional all the way around and it is proven. Now just because you went back to conventional oil and had no problems is great. Its prolly cause you change your oil on a regular basis, but it can screw your seals up. You think someone just made that up, I think not. It isn't marketing hype, if that were true than I wouldn't swear by it. I'm a true believer that Syn is great. Maybe thats why each of my Cylinders were 178-180 on the compression gauge at 111,000. And new its 180 or 185.

 

It has been proven...

 

Still no proof. Thought not.

 

I think someone did make that up...and you're passing on that misinformation. Switching oils will not "screw up your seals"...seals dry out and leak from poor maintenance.

Putting synthetic in a car that already has a seal problem will amplify the problem. The synthetic oils hire level of detergents will clean the gunk out of the crevices causing the seal to leak more than previous, however it had nothing to do with switching the oil and everything to do with the previous level of maintenance.

In a car that has been maintained you can switch back and forth between synthetic and dyno as much as you like. Heck, you can shake it up a little and mix the two with no ill effects whatsoever.

 

Exactly my point, it can cause a leak, you don't know how many miles is on his car neither do I thats why I asked him. So it is about maintaining a vehicle. So my point exactly he doesn't know who owned his car before him to risk taking a chance. So QUOTE : In a car that has been maintained you can switch back and forth between synthetic and dyno as much as you like. Did you mention, if it was not maintained. ???

 

I never said Mobil 1 was a waste. I said that it isn't for me and my engine. Others have good UOA's with it, and that's good for them. I did not, so I switched back to Castrol GTX. Yes, I do change my oil religiously every 3000 miles. If I was interested in extended drain intervals, I might try a heavier synthetic than Mobil 1 5w30. However, I don't mind using conventional oil and changing every 3000 miles. Gives me a chance to inspect the rest of the car while I'm down there. And I'm not spending $4.50/qt for something I won't use (extended drain capability).
The marketing hype I was talking about concerned increased gas mileage claims between a synthetic and conventional oil of the same grade. Some people claim that going from conventional 10w30 to Mobil 1 10w30 gives them better mileage. No, it doesn't, atleast not measurably. The marketing hype is when oil manufacturers claim increased mileage from their synthetic over a conventional. If you read the fine print, the conventional their synthetic is being compared to is a heavier grade. This is where the "hype", or misleading info is. They don't put it in large print where even an idiot would see their 5w30 is being compared to a conventional 10w30. And honestly, how many average people would even notice that difference or know what it means? These are very basic marketing principles; play on people's ignorance, and people generally don't pay much attention to small type. So what Joe the consumer sees is using "brand y" oil will give them better mileage. He's not noticing "brand y" synthetic is being compared to a heavier grade conventional. Nor does he care if he is going to get "better mileage". So he thinks that fact alone justifies the higher cost. He probably won't get a UOA before jumping in to extended drain intervals, either.
Switching from synthetic to conventional does not mess up your seals. Poor maintenance messes up your seals. Oil should be changed based on mileage or time, whichever comes first (and these can vary by driving habits, environment, etc...). This is because the combustion process creates by-products (acids) that are detrimental to internal components. Oils have additive packages to counter-act those by-products. Synthetics generally have more robust additive packages. Conventionals need more VI's (viscosity improvers), and therefore have less "space" in their formula for neutralizing additives. But these additives are used up, and the oil needs changed before they are. This justifies getting an oil analysis to see what a particular engine, driving habit, environment combination is doing to an oil. Oil doesn't just lubricate your engine; it also cleans it.

If anyone needs more info on engine oil, check out the forums (and other info) at www.bobistheoilguy.com. Like any other internet source of info, just don't believe everything you read without getting credible facts first. Even that forum has some people who seem to speak first without having facts to back them up.

Dave

 

Total agree with you sorry I missunderstood you. Its good to know there is people here with knowledge. Meaning Power. I will check out that site, hey you can get mobil one now for 3.47 a quart and walmart and target awesome!!!

 

not being a smartass but how does battery voltage afftect gas mileage? I'm asking because my car might have a bad battery (cranks slow sometimes) and i get 15 mpg without beating on my 03.

 

You must be like 13 years old...not only can you not read a post...you can't read your own post. Here, let me teach you how to quote:

Say anything about maintenance in your post? No. Did you backpeddle your argument? Yes.

"It" can not cause a leak, the leak would be there already.

Right...

Stop spouting your garbage...you're wrong. Move on.

 

OMG...and you're giving advice????

 

Just a note. 30 wt oils go from 9.5 -12.5 cst @100c. Mobil 1 10W30 is a thin (10cst @100c) 30wt oil. It will do just fine in LA. There is a lot that can be learned about motor oils, i.e., viscosity index, TBN, CCS, ACEA/SAE certs and what they mean; the link to "Bobs" is the place to go to be informed about what you put in your vehicle. Just my two cents.

Pedro