Manufacturer's oil weight/temp graph.

[OceanRuns]

Vehicle : 1996 Suzuki X90, 1.6 engine (same as Geo Tracker), 110K miles.

Owner's manual says 10w30 is preferred (temps over -4). But, then in the graph it shows 10w30 and only being effective up to 86 degrees?

Should I go with a 10w-40? Will 10w-40 flow the same as 10w30 on start-up?

Are oils today improved on since 1996 that charts like this are no longer valid?

Thanks.

 

[Dakota1820]

Oil are better I assume you mean Fahrenheit? A lot of times they measure that stuff in celcius. Id say run 10w30 and be happy. I personally don't like 10w40 its got to far of a viscosity spread for my taste. But i drive a car that is brutal on oil some cars it wouldn't matters as much as mine.

 

[brandini]

http://www.amsoil.com/mygarage/vehiclelookup.aspx?url2=1996+SUZUKI+X90+P

I'd say go 5W or 10W-40

 

[Radman]

You should use an oil that falls within the temperature range in your manual. 10W30 & 10W40 will have similar pumpability on start up. 10W40 will have a thicker CST at operating temperature than 10W30.

I use GTX 10W30 in Summer and GTX 5W30 in Winter with an oversized filter on my Suzuki. If I lived in Cali and the temps were averaging above 80 I wouldn't hesitate to use 10W40. Also an oversized Purolator oil filter PL30001 can be used in your application.

 

[CATERHAM]

Originally Posted By: Radman
10W30 & 10W40 will have similar pumpability on start up.

Not so.
It's a common misconception that an oil with the same SAE prefix number such as 10W in this case will have similar start-up viscosities, but in fact the 10W-40 will be much heavier on start-up. The second number has a big impact on the start-up viscosity at typical start-up temp's.

I'd use a good 5w30 synthetic (bought on sale) year round as it will easily handle ambient temp's well in excess of 86F.

 

[Radman]

Similar doesn't equal the same. Yes a 10W40 would be thicker than 10W30 on start up but in high Summer temps it would be negligible.

I wouldn't use syn oil on an old vehicle with high miles.

 

[CATERHAM]

You're still wrong.
Just take a look at the higher KV40 spec's of any 10W-40 grade.

Additionally, the benefits of synthetic oil don't change because an engine has higher mileage.