I have already tried the search function about this topic and got nothing. If this is a reoccuring topic then i apologize in advance. I drive a 94 VTEC prelude which has 130k miles on it. It is time for my next oil change and i was thinking about switching to synthetic. From previous research that i have done i have heard not to do this b/c of the high miles on my car. The reasoning was that the seals are alreay saturated with regular oil and since the molecules are smaller in sythetic oil, that the seals will not expand like normal and i will begin to leak oil. Does this sound right at all? Has anyone heard anything to this effect? Is it okay to change types of oil at high miles? Thanks

 

Yes you can change over. Just use the high mileage stuff. Or 10W 30 or 10W 40.
You almost have the idea right why people say not to use it. When synthetic first came out it was all detergent. This would clean away any buildup that might be keeping a leak sealed. Now they are not all detergent so you can do this fine.

Yes the oil may cause leaks because it has smaller molecules that might get through a small leak more than regular oil did. But because the synthetic molecules are smaller they actually penetrate the gaskets causing them to expand back to their original size. That's a good thing. But if there is a pre-existing leak it may leak worse.

I just changed over to synthetic a few weeks ago. I also just hit 200,000 miles on Tuesday. I have had no problems at all. Runs better if anything. No new leaks or anything at this point. *knock on wood*

 

i really recommend mobil 1 5w-30 for the prelude, especially if you live in a harsh environment and/or you race your prelude, unless your prelude leaks oil. it also improves your mpg(in the long run), prolongs engine life, and you could go up to 7500 miles w/o changing your oil(this varies ofcourse if you obuse your engine and the quality of your oil filter you buy). if it does leak oil then you would be wastin alot of money on the syn oil. also use 5w-30 because the engine was design to operate with that type of oil.

 

I agree,Mobil 1 5w30 is the way to go.It's what your car was designed for(including your oil pump).I've switched back and forth with no problems.


Modified by importsyn at 7:46 PM 9/12/2003

 

thanks, i was about to post a similair question. but my car hasnt been driven for a year so ima throw regular oil in this time to kinda break it back in.

 

Yes I know that the Honda recommends 5W 30 but he was asking about higher mileage. If you use 5W 30 in a higher mileage engine you will most likely leak oil. This is the reason that 10W30 is recommended for engines with higher mileage. No the 10W 30 will not hurt anything. If you run the 10W 30 and there are no leaks and your not burning an excess amount of oil then try running the 5W 30. But I highly recommend that you use the 10W 30 at least the first time you change over to synthetic if you have over 100k miles. This will also give the seals more time to expand sealing most possible leaks.

 

i use mobil 1 10w30. im not sure if i would want to go 5w30 cuz its a higher mileage engine. thats why i choose 10w30. im not really sure if i should go 5w30 or not. and btw, what oil filters do u guys use? do u use the mobil 1 filter or do u use oem honda filters? and also... since i use synthetic now, that means i can change my oil every 7500 miles instead of 3000?? cuz ive been changing it every 3000 miles, even with my synthetic. i guess its ok for me to change my oil every 7500 miles now? thanx

 

I just put in AmsOil 10w40 in my newly rebuilt motor after a 2700 mile break in on conventional oil.

I know it is a little heavier weight, is that going to be an issue?

 

10w30 won't hurt it's when you start running 15w50 or thicker that things start to get scary,UNLESS your motor is built for that.I agree with the other statments as well about higher mileage engines,let's face most of them have had a hard life so you have to compensate in some way.But switching back and forth won't be a problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidNiteMysT &raquo;</TD></TR><TR><TD CLASS="quote">i use mobil 1 10w30. im not sure if i would want to go 5w30 cuz its a higher mileage engine. thats why i choose 10w30. im not really sure if i should go 5w30 or not. and btw, what oil filters do u guys use? do u use the mobil 1 filter or do u use oem honda filters? and also... since i use synthetic now, that means i can change my oil every 7500 miles instead of 3000?? cuz ive been changing it every 3000 miles, even with my synthetic. i guess its ok for me to change my oil every 7500 miles now? thanx</TD></TR></TABLE>

 

I switched to Mobil 1 on my 96 VTEC around 80,000 miles and after 10-15,000 I switched back to conventional. With the amount of oil was burning it was cheaper to buy conventional and chanhe it more frequently.

 

THERE ya go! This guy has the right stuff.. Amsoil is THE best, period.

Nah man the 10w40 will be fine. That's what I use. Sucks they don't have the good 10w30 but what can ya do?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Prelude Styl &raquo;</TD></TR><TR><TD CLASS="quote">Amsoil is THE best, period.</TD></TR></TABLE>

o, is that why mobil 1 comes stock in lots of performance cars?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidNiteMysT &raquo;</TD></TR><TR><TD CLASS="quote">

o, is that why mobil 1 comes stock in lots of performance cars? </TD></TR></TABLE>

do you know how much mobile pays to have them use their oil?

 

yea maybe, but im sure a dodge viper or mercedes wouldnt put a shitty oil in their cars even if they got paid. those cars do require some qaulity.