what fuel octane do you run in your 4.0 i6 and why?

Ryan Marshall
195

Asked by Sep 15, 2009 at 04:46 PM about the Jeep Grand Cherokee

Question type: General

5 Answers

Andrew Hartman
215

87. It's the cheapest and the 4.0 is a 35 year old design that does not require anything higher for performance. Anything more than 87 is just wasting money.

Ryan Marshall
195

thx for your response. i was making sure because ive heard mixed responses.

Nathan Casteel
75

Don't use 90 octane. Just use Unleaded 87 octane. Using a higher octane fuel is only more expensive, and instead of conserving fuel, it will only burn/use it faster. The inline 6 was only meant to have 87, and it could possibly overwork your engine if you try and go higher. Besides, 87 is the cheapest... why spend more?

cliff212
70

I was told by a mechanic to use only reg (85 OR 87 OCT) and not to use the 10% ethenol as this causes the senors to assume that the engine is running lean and will increase the fuel consumption until the 02 sensor is satisfied. I have a 99 with 83K and has not had anything but regular in it. Still runs exceptionally well.

1 out of 1 people think this is helpful.
chrisnemo
0

i live in sweden and the low octane here is 95,i run my grand cherokee laredo 4,0 on this,no problems,87 or 89 octane can be had in former east europe or russia,but not in the west,95 gives you a lot of pulling and towingpower

Your Answer

Add photo

Related Questions

  • how long does a grand cherokee last? (mileage wise) 23 answers

    how long does a grand cherokee 1999 last? (mileage wise) i would like to buy one but do you know if this car have some problem ??? thanks

    1999 Jeep Grand Cherokee Laredo 4WD

    -

    General

  • Why 93 Grand Cherokee Laredos? 2 answers

    Hi, I just recovered my 93 Grand Cherokee Laredo after it was stolen two weeks ago. I come to find that the 93 Jeep Grand Cherokee Laredo is the 9th most popular car to be stolen in Washington state. ...

    1993 Jeep Grand Cherokee Laredo 4WD

    -

    General

  • why does my jeep shake mostly while idling? 1 answer

    Ok i just did a block swap and got.the.truck running . new.head gasket set. but now jeeps motor is jumpy so tightened the mounts.i noticed most of the noise was coming from the exhaust. Engine ligh...

    1999 Jeep Grand Cherokee Laredo 4WD

    -

    General

  • 2007 Jeep Grand Cherokee shuts off and then restarts itself 1 answer

    My mother has a 2007 Jeep Grand Cherokee and it was idling in the driveway and it shut off and then restarted itself without her touching the key. Why does this do this and what may be the cause?. It...

    2007 Jeep Grand Cherokee Laredo 4WD

    -

    General

  • Is a 99 jeep cherokee witha Inline 6 a good choice??? 30 answers

    Looking to buy one for the wife! Is it a good motor? Reliable? Gas mileage? THANKS

    1999 Jeep Grand Cherokee Laredo

    -

    Shopping & Pricing

Grand Cherokee
Looking for a Used Grand Cherokee in your area?
CarGurus has 67,486 nationwide Grand Cherokee listings starting at $900.
ZIP:

Search Jeep Grand Cherokee Questions

Jeep Grand Cherokee Experts

#1 Tom Demyan
Tom Demyan
Reputation 1,270
#1 inuevafreak
inuevafreak
Reputation 1,270
#3 FordNut
FordNut
Reputation 1,250
View All

Related Models For Sale

Used Jeep Cherokee"
201 Great Deals out of 51,657 listings starting at $2,000
Used Jeep Wrangler"
611 Great Deals out of 55,108 listings starting at $1,500
Used Ford Explorer"
592 Great Deals out of 51,109 listings starting at $1,495
Used Toyota 4Runner"
241 Great Deals out of 13,235 listings starting at $1,875
Used Chevrolet Tahoe"
566 Great Deals out of 31,225 listings starting at $1,500
Used Dodge Durango"
234 Great Deals out of 20,491 listings starting at $988
Used Dodge Charger"
440 Great Deals out of 33,614 listings starting at $2,500
Used Ford F-150"
2,433 Great Deals out of 196,747 listings starting at $1,595
Used Jeep Liberty"
284 Great Deals out of 9,204 listings starting at $1,495
Used BMW X5"
255 Great Deals out of 10,593 listings starting at $2,799
Used Chevrolet Silverado 1500"
1,742 Great Deals out of 126,526 listings starting at $2,000
Used Ford Mustang"
307 Great Deals out of 47,191 listings starting at $1,100
Used Jeep Commander"
68 Great Deals out of 2,088 listings starting at $4,695
Used Jeep Patriot"
316 Great Deals out of 32,673 listings starting at $3,250
Used Honda Accord"
590 Great Deals out of 72,886 listings starting at $800