Honda Accord 4 cyl Vs. Audi 4 Cyl (Another Gas Question)
02-15-2005, 08:21 PM
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Honda Accord 4 cyl Vs. Audi 4 Cyl (Another Gas Question)
2005 Audi 4cyl has compression ratio of 9.3 to 1
2005 Honda Accord has compression ration of 9.7 to 1
WHY does Audi recommend premium fuel ( http://auto.consumerguide.com/auto/n...x.cfm/id/37495 )
and Honda does not? [since I heard a lot of talk here how compression ratio has ALL to do with what gas to use].
Thx
2005 Honda Accord has compression ration of 9.7 to 1
WHY does Audi recommend premium fuel ( http://auto.consumerguide.com/auto/n...x.cfm/id/37495 )
and Honda does not? [since I heard a lot of talk here how compression ratio has ALL to do with what gas to use].
Thx
02-16-2005, 05:00 AM
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"Audi recommends premium-grade fuel for all A4s."
1.8T engine has a turbo. So pressure at the end of compression will be higher.
AUDI Engine is 1.8 vs. 2.4 on Honda so turbo puts noticable pressure.
3.0 engine has 10.1 ratio.
I would imagine that is why.
1.8T engine has a turbo. So pressure at the end of compression will be higher.
AUDI Engine is 1.8 vs. 2.4 on Honda so turbo puts noticable pressure.
3.0 engine has 10.1 ratio.
I would imagine that is why.
02-16-2005, 05:40 AM
#3
Compression ratio is important, but it's not the only thing that matters. Combustion chamber shape, spark location, cam profiles, spark timing, turbo (of course). Compression ratio & boost are probably the most important, tho.
02-16-2005, 07:23 PM
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Ignition timing is typically the main factor there. Shape of the combustion chamber and piston are also important.
I have a 12.5:1 compression ratio on my motorcycle and it runs OK with 89 octane.
I have a 12.5:1 compression ratio on my motorcycle and it runs OK with 89 octane.
