ok i just bought a 1990 gmc sierra and ive had it for a month now and i need to add oil maybe even get it changed.the guy i bought it off of says he put 5w 30 synthetic oil in it.i kno synthetic is a little better but is it safe to put that in an 18 yr old truck?the engine is a 5.7 350 with a good amount of miles.so if i decide to get my oil changed now should i put synthetic or go back to conventional?
2007-07-06 14:25:36 · 10 answers · asked by matt 1 in Cars & Transportation ➔ Maintenance & Repairs
is it safe to switch between the 2 if i get it my oil changed and put conventional in it? (as u could guess im not an engine guy)
2007-07-06 14:34:37 · update #1
It's your choice, if you don't want to put the expensive stuff in it, don't. Personally I think I would use what he did to make it last this long he must have done something right.
2007-07-06 14:32:49 · answer #1 · answered by mister ss 7 · 0⤊ 1⤋
Synthetic oil is better. The question is, is it enough better for your older truck to justify the expense? No. If it were my truck, I'd use good name-brand conventional oil and change it every 6000 miles.
2007-07-06 22:43:44 · answer #2 · answered by Anonymous · 0⤊ 0⤋
safe but costly
try conventional with "slick-50" additive
replace 1 qt oil with the slick 50. its great stuff ., Ran a engine with busted oil pump for 20 hard miles with no damage
2007-07-06 21:48:23 · answer #3 · answered by cheyenne95129 3 · 0⤊ 0⤋
I'd stick with regular oil...it's 1/3 the price and a 1990 usually uses enough oil that the price difference will add up fast.
2007-07-06 21:30:02 · answer #4 · answered by Anonymous · 0⤊ 1⤋
I own A 1995 1500 with a 350.Have over 200 k on it and only use mobile 1 5W30.It helps keep the engine cleaner because of the deturgants.I also work on gm cars and trucks.It can only help with that much age on it.
2007-07-06 21:35:15 · answer #5 · answered by bluelitnin 2 · 0⤊ 1⤋
its your call but synt is better but i would get 10w40 oil. i drive 130 miles a day for work and the 2 cars that i drive have 200 on them. i use castrol 10w40 in both with no problems
2007-07-07 03:24:22 · answer #6 · answered by chucky 2 · 0⤊ 0⤋
my 1988 olds has alot of miles on it, so i use high mileage oil in it. if i were you i would use that and go to 10w30, it would be better for that older truck.by the way, thats a nice truck.
2007-07-07 00:48:45 · answer #7 · answered by Anonymous · 0⤊ 0⤋
Keep with the synthetic it is better at lubricating, and you can go more miles between changes
2007-07-06 21:29:52 · answer #8 · answered by Pengy 7 · 0⤊ 1⤋
If it's been using synthetic oil, there's no harm in continuing to use it.
2007-07-06 21:32:41 · answer #9 · answered by Scott H 7 · 0⤊ 1⤋
you should have changed the oil the day you bought it
2007-07-10 06:02:14 · answer #10 · answered by jjohnny65 3 · 0⤊ 0⤋