10w/40
This is not advised. Use 10w30.
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The engine computer is the voltage regulator.
The 40. 1997 Jeep Wrangler needs 6 quarts of oil for an oil change.
Running at operating temperature around 40 psi.
about 20psi at idle (warm) and 40 to 50psi at 2000rpm.
A full operating temperature it will be around 40 psi.
Use any good 15-40 W engine oil intended for motorcycles. Change oil according to the owner's manual. I would change the engine oil every 3 to 4 thousand km on this bike. For a worn engine and hot outside temperatures, a 20-40 or even single grade 40 W can be used.
50 50 coolant is what i use- would suggest no more han a 60 40 mix.
Around 30-40 psi when at full operating temperature. Can even be somewhat lower on a high mileage engine.
1990/20 ÷ 20 = 199/40 or 439/40