Motor Oil - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

fodive · 06-27-2002, 09:30 PM

since my 91 240 has 160,xxx miles on it, most people recomend running a 10X30  type oil, but i was wondering if running a full synthetic performance oil would hur tmy car because of hte high miles?

*DSC* · 06-27-2002, 09:36 PM

It won't hurt the engine, but synthetic has been known to leak when used in high mileage engines that use dino oil.
From what I've read, it would be best to use a high quality 10w30 dino oil instead of synthetic in your situation.

guidot · 06-27-2002, 11:51 PM

This is what I have heard....
Synthetic is no good in high mileage engines...it causes seals to shrink, thus the leak that DSC speaks of.  
The best oil for high mileage cars is Valvoline MaxLife...supposedly it expands the seals, stopping or slowing those leaks...but a standard oil is always good too...I use Castrol GTX.

rotaryknight · 06-28-2002, 12:29 AM

You might want to go a little heavier 20w50 is good for high mileage cars.  10w40 is crap don't use that though.

pete north · 07-03-2002, 09:13 AM

Valvoline MaxLife is NOT a good oil. It's just another case of advertising in hopes that people will buy without researching. (like most of the engine treatments out there, slick50, ProLong, etc...)

It's additive that supposedly reconditions seals can over-soften your seals causing even more problems than you had in the first place (if you even had a problem in the first place).

If you beleive what people say about synthetics shrinking your seals (I don't) then why not go with a quality conventional 5w-30 such as Castrol GTX? It's a better oil than 10weight.

06-27-2002, 09:30 PM	#1
fodive Zilvia Junkie Join Date: Jun 2002 Location: Columbia, SC Age: 39 Posts: 548 Trader Rating: (0) Feedback Score: 0 reviews	since my 91 240 has 160,xxx miles on it, most people recomend running a 10X30  type oil, but i was wondering if running a full synthetic performance oil would hur tmy car because of hte high miles? __________________ roots.

06-27-2002, 09:36 PM	#2
DSC New Title Join Date: Aug 2001 Location: VA Posts: 3,454 Trader Rating: (0) Feedback Score: 0 reviews	It won't hurt the engine, but synthetic has been known to leak when used in high mileage engines that use dino oil. From what I've read, it would be best to use a high quality 10w30 dino oil instead of synthetic in your situation. __________________

06-27-2002, 11:51 PM	#3
guidot Zilvia Junkie Join Date: Feb 2002 Location: Cape Cod, MA Age: 44 Posts: 443 Trader Rating: (0) Feedback Score: 0 reviews	This is what I have heard.... Synthetic is no good in high mileage engines...it causes seals to shrink, thus the leak that DSC speaks of.   The best oil for high mileage cars is Valvoline MaxLife...supposedly it expands the seals, stopping or slowing those leaks...but a standard oil is always good too...I use Castrol GTX. __________________ -Jeff T. 96 240SX 240SXONE http://www.240sxone.com

06-28-2002, 12:29 AM	#4
rotaryknight Zilvia Junkie Join Date: Apr 2002 Posts: 408 Trader Rating: (0) Feedback Score: 0 reviews	You might want to go a little heavier 20w50 is good for high mileage cars.  10w40 is crap don't use that though. __________________ Daily Driver- 91 240 SX SE...S13 Blacktop HKS FMIC, EVC IV, W/G, Racing Suction, DP, Dual Drager, springs/pillow ball mounts Whiteline sway bars Tokico blues Koyo Radiator, Fluidyne fan J30 VLSD stock exterior. Fun Car- 94 FD3S (TO4S). The White HKS FD in FnF......may she rest in pieces.

07-03-2002, 09:13 AM	#5
pete north Join Date: Mar 2002 Posts: 39 Trader Rating: (0) Feedback Score: 0 reviews	Valvoline MaxLife is NOT a good oil. It's just another case of advertising in hopes that people will buy without researching. (like most of the engine treatments out there, slick50, ProLong, etc...) It's additive that supposedly reconditions seals can over-soften your seals causing even more problems than you had in the first place (if you even had a problem in the first place). If you beleive what people say about synthetics shrinking your seals (I don't) then why not go with a quality conventional 5w-30 such as Castrol GTX? It's a better oil than 10weight.